Answer:
Explained below.
Explanation:
Let the initial velocity from the top of the tower of height(h) be u'
Now, since it is projected horizontally, the horizontal distance covered will be due to having a uniform horizontal velocity (u) while it will possess a vertical distance in the downward direction due to constant acceleration due to gravity (g).
If the time it takes the ball to reach the ground is "t", then we can say the horizontal distance travelled by the ball is denoted as; x(t) = x, while the vertical distance is denoted by; y(t) = y
Now, since it's a projectile the intial velocity (u) will have vertical and horizontal components which are;
u_y and u_x respectively.
Applying kinematic equations, we have;
x = u_x•t + ½at²
Acceleration is zero in the horizontal x direction. Thus;
x = u_x•t
For the vertical y-direction;
y = u_y•t + ½at²
Here since direction is in that of gravity, then a = g.
Also, since the initial velocity has no downward component, then u_y = 0 m/s
Thus;
y = ½gt²
From x = u_x•t, we have;
t = x/u_x
Thus;
y = ½g(x/u_x)²
y = ½gx²/(u_x)²
Let g/(u_x)² be treated as a constant with the letter k.
Thus;
y = kx²
This is the form of a parabolic equation.
Thus, it has been proved that the projectile follows the path of a parabola.
Presence of _______- in retina gives us night vision that is help us to see in dim light.Required to answer. Single choice. Immersive Reader (1 Point) cornea retina lens rods
Answer: Rods
Explanation:
The rod cells in the retina are the reason we are able to see at night and in dim light. They exist on the edges of the retina which is why they are also very useful for the peripheral vision of a human.
Rod cells number over 90 million in the eyes and although very useful for seeing in dimmer light, they are not very useful for color vision which is why humans see less colors in the dark.
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Ariana is accelerating her car at a rate of 4.6 m/s2 for 10 seconds. Her starting velocity was 0 m/s.
What was her final velocity?
0 m/s
2.3 m/s
4.6 m/s
46 m/s
Answer:
46
Explanation:
v = at so 4.6 x 10 = 46
Mains electricity is an ac supply. Explain the difference between direct and alternating potential difference.
Direct current (DC) is the flow of electric charge in only one direction. It is the steady state of a constant-voltage circuit. Most well-known applications, however, use a time-varying voltage source. Alternating current (AC) is the flow of electric charge that periodically reverses direction.
#LETS STUDYMatch the synthetic materials with the processes used to make them.
Imagine you see Mars rising in the east at 6:30 pm. Six hours later what direction would you face (look) to see Mars when it is highest in the sky
Answer:
The Mars appears in the direction of South.
Explanation:
Mars is rising in the east at 6: 30 PM. The period of rotation of earth is 24 hours.
So, 6 hours is the one fourth of the period of rotation of earth. Earth rotates counter clockwise on its axis, so after 6 hours, we see the Mars in the direction of South.
If you are driving 90 km/hkm/h along a straight road and you look to the side for 2.8 ss , how far do you travel during this inattentive period
Answer:
Distance = 70 meters
Explanation:
Given the following data;
Speed = 90 km/h
Time = 2.8 seconds
Conversion:
90 km/h to meters per seconds = 90 * 1000/3600 = 90000/3600 = 25 m/s
To find the distance covered during this inattentive period;
Speed can be defined as distance covered per unit time. Speed is a scalar quantity and as such it has magnitude but no direction.
Mathematically, speed is given by the formula;
[tex]Speed = \frac{distance}{time}[/tex]
Making distance the subject of formula, we have;
[tex] Distance = speed * time [/tex]
Substituting into the above formula, we have;
[tex] Distance = 25 * 2.8 [/tex]
Distance = 70 meters
What is the form of the main energy output from the reactor?
Explanation:
A nuclear reactor produces and controls the release of energy from splitting the atoms of certain elements. In a nuclear power reactor, the energy released is used as heat to make steam to generate electricity.
Two lenses having f1:F2=2:3 has combination to make no dispersion.Find the ratio of their dispersive power?a)2:3 b)3:2 c)4:9 d)9:4
Answer:
b)3:2
Explanation:
The dispersive power is the reciprocal of the focal length:
[tex]P=\frac{1}{f}[/tex]
Given the ratio of focal lengths:
[tex]\frac{f_1}{f_2} = \frac{2}{3}\\\\\frac{\frac{1}{P_1}}{\frac{1}{P_2}}=\frac{2}{3}\\\\\frac{P_2}{P_1}=\frac{2}{3}\\\\\frac{P_1}{P_2}=\frac{3}{2}[/tex]
Therefore,
P₁ : P₂ = 3 : 2
Hence, the correct option is:
b)3:2
at which point is the Kinetic energy the lowest?
Answer:
the lowest kinetic energy point is option D
A box has a mass of 4kg and surface area 4m². Calculate the
pressure exerted by the box on the floor.
Answer:
10 pa
Explanation:
4kg* 10 (or 9.8m/s2) = 40
40N /4m2 =10
What is the colour of a shirt which has blue and white stripes when put under yellow light? Explain.
Answer:
Black and yellow strips.
Explanation:
Color of shirt is blue and white stripes
When the shirt is seen in the yellow light, the blue color do not reflect any color so it appears black and the white color reflects the yellow light so it appears yellow.
Thus, the color of shirt is blue appears black and white appears yellow.
10. If the mass of the Earth is... increased by a factor of 2, then the Fgrav is ______________ by a factor of _______. ... increased by a factor of 3, then the Fgrav is ______________ by a factor of _______. ... decreased by a factor of 4, then the Fgrav is ______________ by a factor of _______.
Answer:
If the mass of the Earth is increased by a factor of 2, then the Fgrav is increased by a factor of 2.
If the mass of the earth is increased by a factor of 3, then Fgrav is increased by a factor of 3.
If the mass of the earth is decreased by a factor of 4, then the Fgrav is decreased by a factor of 4
Explanation:
In order to solve this question, we must take into account that the force of gravity is given by the following formula:
[tex]F_{g0}=G \frac{mM_{E0}}{r^{2}}[/tex]
So if the mass of the earth is increased by a factor of 2, this means that:
[tex]M_{Ef}=2M_{E0}[/tex]
so:
[tex]F_{gf}=G \frac{2mM_{E0}}{r^{2}}[/tex]
Therefore:
[tex]\frac{F_{gf}}{F_{g0}}=\frac{G \frac{2mM_{E0}}{r^{2}}}{G \frac{mM_{E0}}{r^{2}}}[/tex]
When simplifying we end up with:
[tex]\frac{F_{gf}}{F_{g0}}=2[/tex]
so if the mass of the Earth is increased by a factor of 2, then the Fgrav is increased by a factor of 2.
If the mass of the earth is increased by a factor of 3
So if the mass of the earth is increased by a factor of 2, this means that:
[tex]M_{Ef}=3M_{E0}[/tex]
so:
[tex]F_{gf}=G \frac{3mM_{E0}}{r^{2}}[/tex]
Therefore:
[tex]\frac{F_{gf}}{F_{g0}}=\frac{G \frac{3mM_{E0}}{r^{2}}}{G \frac{mM_{E0}}{r^{2}}}[/tex]
When simplifying we end up with:
[tex]\frac{F_{gf}}{F_{g0}}=3[/tex]
so if the mass of the Earth is increased by a factor of 3, then the Fgrav is increased by a factor of 3.
If the mass of the earth is decreased by a factor of 4
So if the mass of the earth is decreased by a factor of 4, this means that:
[tex]M_{Ef}=\frac{M_{E0}}{4}[/tex]
so:
[tex]F_{gf}=G \frac{mM_{E0}}{4r^{2}}[/tex]
Therefore:
[tex]\frac{F_{gf}}{F_{g0}}=\frac{G \frac{mM_{E0}}{4r^{2}}}{G \frac{mM_{E0}}{r^{2}}}[/tex]
When simplifying we end up with:
[tex]\frac{F_{gf}}{F_{g0}}=\frac{1}{4}[/tex]
so if the mass of the Earth is decreased by a factor of 4, then the Fgrav is decreased by a factor of 4.
TRUE OR FALSE. if an object does not change its position at a given time interval, then it is at rest or its speed is zero or not accelerating
Answer:
true
Explanation:
a body can only be accelerating and have speed if it's in motion
An acceptable radiograph was taken using 40 mAs at 80 kVp at a distance of 60 inches. A second radiograph is requested at 40 inches. What mAs should be used to produce this radiograph with a 40-inch distance
Answer:
17.8 mAs
Explanation:
The exposure maintenance formula shows that as SID increases, intensity decreases, causing a decrease in film exposure and density. The mAs is directly proportional to the square of the distance. That is as mAs increases, distance increases, and vice versa, in order to maintain image receptor exposure. It is given by:
[tex]\frac{mAs_1}{mAs_2}=\frac{D_1^2}{D_2^2}[/tex]
Given that mAs₁ = original mAs = 40 mAs, D₁ original distance = 60 in, D₂ = new distance = 40 in, mAs₂ = new mAs
[tex]\frac{mAs_1}{mAs_2}=\frac{D_1^2}{D_2^2}\\\\mAs_2=\frac{mAs_1*D_2^2}{D_1^2}=\frac{40*40^2}{60^2}=17.8\\\\mAs_2=17.8\ mAs[/tex]
what is good operating practice concerning the use of aircraft lighting while on the ground at night
Answer:
It is important to be extra careful at night and in periods of low visibility from sunset to sunrise and to focus on operating the aircraft safely when the aircraft is moving. Ensure checklist are run through and avoid non essential communications prior to the aircraft being stopped and the breaks are set
Explanation:
According to aircraft rules and regulation, the position lights of an aircraft are required to be switched on on an aircraft which is either operated on the surface and during flight from sunset to sunrise or when the elevation of the Sun below the horizon is more than 6°
However, the anti collision lights are not required to be lighted during night operations, unless the pilot in command specifies it for safety reasons
What is the size of the force acting on a copper wire with a magnetic flux density of 3.6 x 10-2 T acting at
right angles to the wire of length 24 m and current of C:048 A? Give your answer to an appropriate
number of significant figures.
Answer:
F = 0.414 N
Explanation:
Given that,
Magnetic flux density,[tex]B=3.6\times 10^{-2}\ T[/tex]
The length of the wire, l = 24 m
Current, I = 0.48 A
We need to find the force acting on the wire. The formula for the force is given by:
[tex]F=ILB[/tex]
Put all the values,
[tex]F=0.48\times 24\times 3.6\times 10^{-2}\\\\F=0.414\ N[/tex]
So, the force acting on the copper wire is equal to 0.414 N.
The magnetic force of the copper wire is 41.472 N.
Magnetic force of the copper wire
The magnetic force of the copper wire is calculated by applying the following equation.
F = BIL x sinθ
Where;
θ is the inclination of the magnetic fieldI is the currentL is the length of the wireB is the magnetic field strength = flux densityF = (3.6 x 10⁻²) x (48) x 24 x sin(90)
F = 41.472 N
Thus, the magnetic force of the copper wire is 41.472 N.
Learn more about magnetic force here: https://brainly.com/question/13277365
If a rock has a speed of 12 m/s as it hits the ground, from what height did it
fall, assuming its initial speed was zero? Its mass is 50 kg.
A. 600 m
B. 4.2 m
C. 12 m
D. 7.3 m
Answer:
To find the height the following formula should be used:
v 2 = u 2 + 2aH
Explanation:
Assuming this occurs on earth, a= 9.8 ms -2
-2 2
12=0+2 x9.8 x H
144
_______ =H
2 x 9.8
H= 7.35m
Mean diameter of cylinder measured by A is 2.50 cm with a possible error of 0.25 cm whereas mean height of cylinder measured by B is 10.0 cm with a possible error of 0.5 cm. Whose measurement is more accurate?
Answer:
The measurement of first cylinder is more accurate.(A)
Explanation:
The least possible error higher will be accuracy.
A fuse in an electric circuit is a wire that is designed to melt, and thereby open the circuit, if the current exceeds a predetermined value. Suppose that the material to be used in a fuse melts when the current density rises to 540 A/cm2. What diameter of cylindrical wire should be used to make a fuse that will limit the current to 0.57 A
Answer:
0.0366 m
Explanation:
We are given;
Current density; J = 540 A/cm² = 540 × 10⁴ m
Current; I = 0.57 A
Now, formula for current density is;
J = I/A
Where A is area = πr²
Thus;
J = I/(πr²)
r = √(I/(Jπ))
r = √(0.57/(540π))
r = 0.0183 m
Diameter = 2 × radius
Diameter = 2 × 0.0183
Diameter = 0.0366 m
: Một mặt phẳng vô hạn tích điện đều, mật độ σ = 4.10-9 C/cm2, đặt thẳng đứng trong không khí. Một quả cầu nhỏ có khối lượng 8 g, mang điện tích q = 10-8 C treo gần vào mặt phẳng, sao cho dây treo lúc đầu song song với mặt phẳng. Lấy g = 9,8m/s2. Khi cân bằng, dây treo quả cầu hợp với mặt phẳng 1 góc bằng bao nhiêu?
Answer:
The angle is 16 degree.
Explanation:
A uniformly charged infinite plane, density σ = 4.10-9 C/cm2, is placed vertically in air. A small ball of mass 8 g, with charge q = 10-8 C, hangs close to the plane, so that the string is initially parallel to the plane. Take g = 9.8m/s2 . In equilibrium, by what angle does the string hanging from the ball make an angle with the plane?
Surface charge density, σ = 4 x 10^-9 C/m^2
charge, q = 10^-8 C
mass, m = 0.008 kg
Let the tension is the string is T and the angle is A.
[tex]T sin A = q E....(1)\\\\T cos A = m g .... (2)\\\\Divie (1) by (2)\\\\tan A =\frac{q E}{m g}\\\\tan A = \frac{10^{-8}\times 4\times 10^{-5}}{2\times 8.85\times 10^{-12}\times 0.008\times9.8}\\\\tan A = 0.288\\\\A = 16 degree[/tex]
In a science museum, a 130 kg brass pendulum bob swings at the end of a 14.4 m -long wire. The pendulum is started at exactly 8:00 a.m. every morning by pulling it 1.7 m to the side and releasing it. Because of its compact shape and smooth surface, the pendulum's damping constant is only 0.010kg/s. You may want to review (Pages 405 - 407) . Part A At exactly 12:00 noon, how many oscillations will the pendulum have completed
Answer:
The time in which the pendulum does a complete revolution is called the period of the pendulum.
Remember that the period of a pendulum is written as:
T = 2*pi*√(L/g)
where:
L = length of the pendulum
pi = 3.14
g = 9.8 m/s^2
Here we know that L = 14.4m
Then the period of the pendulum will be:
T = 2*3.14*√(14.4m/9.8m/s^2) = 7.61s
So one complete oscillation takes 7.61 seconds.
We know that the pendulum starts moving at 8:00 am
We want to know 12:00 noon, which is four hours after the pendulum starts moving.
So, we want to know how many complete oscillations happen in a timelapse of 4 hours.
Each oscillation takes 7.61 seconds.
The total number of oscillations will be the quotient between the total time (4 hours) and the period.
First we need to write both of these in the same units, we know that 1 hour = 3600 seconds
then:
4 hours = 4*(3600 seconds) = 14,400 s
The total number of oscillations in that time frame is:
N = 14,400s/7.61s = 1,892.25
Rounding to the next whole number, we have:
N = 1,892
The pendulum does 1,892 oscillations between 8:00 am and 12:00 noon.
a motorcyclist drives from A to B with a uniform speed of 30 km/h and returns back with a speed of 20km/h-¹ find the average speed ?
PLEASE DO IT AS FAST YOU CAN AND NO SCAM ANSWERS OR ELSE I WILL REPORT
Answer:
Average speed = 24 km/h
Explanation:
Let the distance be x.Given the following data;
Uniform speed A = 30 km/h
Uniform speed B = 20 km/h
To find the average speed;
Mathematically, the average speed of an object is given by the formula;
[tex] Average \; speed = \frac {total \; distance}{total \; time} [/tex] ..... equation 1
Total time = TA + TB
[tex] T_{A} = \frac {x}{30} [/tex]
[tex] T_{B} = \frac {x}{20} [/tex]
[tex] Total \; time = \frac {x}{30} + \frac {x}{20} [/tex]
[tex] Total \; time = \frac {5x}{60} [/tex]
Total distance = x + x
Total distance = 2x
Substituting the values into equation 1;
[tex] Average \; speed = \frac {2x}{\frac {5x}{60}} [/tex]
[tex] Average \; speed = \frac {2x*60}{5x} [/tex]
[tex] Average \; speed = \frac {120}{5} [/tex]
Average speed = 24 km/h
A vehicle starts from rest with a uniform acceleration of 2m/s2.Find the final velocity of the vehicle after covering a distance of 400m
Answer:
40
Explanation:
vi=0
a=2
vf=?
d=400
vf^2=vi^2+2ad
vf^2=0+2×2×400=1600
vf=√1600=40m/s
A ball tied on a string rotates in a circular path as shown above. The only forces acting on the ball at any point are the weight and of the string. What is the equation for the net centripetal force at point C?
Answer:
the third one T-W
Explanation:
the direction of the Tension and weight are opposite
Name the physical quantity and write its SI unit which gives the slope Of I-V graph?
Slope of I-V graph is Resistance.
Its S.I. unit is Ohm.
The symbol of ohm is Ω.
a ball is launched from the ground with a horizontal speed of 30 m/s and a vertical speed of 30 m/s. what is the balls overall speed at the top of its trajectory?
Answer:
30m/ s
Explanation:
this is an example of a projectile, where the path traced by the ball will be a downward parabola.
one must know that the vertical velocity of an object having projectile motion is zero at the top of its trajectory and that the horizontal velocity remains constant throughout.
this means, at the top of the trajectory the ball's overall speed will be equal to its horizontal velocity.
and horizontal velocity is given 30 m/s
hence, overall speed of the ball = 30m/ s
1. Use a micrometer to find the thickness of the foil you used. Do your data confirm the measured thickness? Determine the percentage difference between the measured thickness and the thickness you found in your experiment.
Answer:
Yes.
Explanation:
Yes, my data confirm the measured thickness because the micrometer measure precise thickness of any object. If the same instrument and right method is used for the measurement of the thickness of the foil then there is zero difference occur between the measured thickness and the thickness in your experiment so using right method can reduce or eliminate the difference between the measured thickness and the thickness in experiment.
Try working backward from the desired goal to the starting point or current state. This advice describes a
Answer:
heuristic.
Explanation:
Psychology can be defined as the scientific study of both the consciousness and unconsciousness of the human mind such as feelings, emotions and thoughts, so as to understand how it functions and affect human behaviors in contextual terms.
This ultimately implies that, psychology focuses on studying behaviors and the mind that controls it.
A heuristic is an automatic mental shortcut or rule of thumb that avail people the opportunity to make quick and efficient judgement in decision-making process, as well as proffering solutions to a problem. Thus, it allows people to make decisions, pass probability judgement or proffer solutions to problem quickly and efficiently while applying minimal mental effort.
Basically, a heuristic helps an individual to shorten the decision-making time while paying less attention on thinking of his or her next course of action.
Hence, when you're advised to try working backward from the desired goal to the starting point or current state. This advice describes a heuristic.
why does a desert cooler cool better than a hot dry day
On a hot dry day, the amount of water vapour present in atmosphere is less. Thus, water present inside the desert cooler evaporates more, thereby cooling the surroundings more. Hence, a desert cooler cools better on a hot dry day.
what do you think will happen to the people in the airplane if their location is unknown?
Question:
What do you think will happen to the people in the airplane if their location is unknown?
My opinion:
I mean what are the circumstances? Is it just a rogue pilot that takes a random plane with all the passengers Hostage or is It bad whether an they lose connection to the airport? I Mean either way, If I was on a plane being held hostage, or the plane crashing, I Would be a in a panic type state of mind. I Would be worried about what will happen when the plane crashes, I would worry about my friends or family that is aboard the plane with me, I Would be scared for my life because I Don't know if i would make it out alive.
Also:
How would they know their location is unknown wouldn't the Pilot be the only one to know exactly where there with their navigating system, But then again there was this time I headed to Florida an They had mini tv's on the seats of each chair, where you could: Watch movies, listen to music, an Also see exactly where you are in the world. It was really amazing actually.
