Answer:
1.) h = 164.8 m
2.) U = 49.1 m/s
3.) t = 1.43 seconds
Explanation:
1.) A soccer ball is dropped from the top of a building. It takes 5.8 seconds to fall to the ground. The height of the building is...?
Since the soccer ball is dropped from the building, the initial velocity U will be equal to zero
Using second equation of motion
h = Ut + 1/2gt^2
Substitutes the time into the formula
h = 1/2 × 9.8 × 5.8^2
h = 164.8 m
2. The Falcon 9 launches to a height of 123 meters. What is its vertical initial velocity?
At maximum height final velocity = 0
Using the third law of motion
V^2 = U^2 - 2gH
0 = U^2 - 2 × 9.8 × 123
U^2 = 2410.8
U = 49.1 m/s
3. An apple falls from rest off a 10.m m tree. How long will it take before it hits the ground?
Since the apple fall from rest, the initial velocity U will be equal to zero
Using the second equation of motion,
h = Ut + 1/2gt^2
substitute all the parameters into the formula
10 = 1/2 × 9.8 × t^2
10 = 4.9t^2
t^2 = 10/4.9
t^2 = 2.04
t = 1.43 seconds
Answer:
B. Thermal energy
E. Sound energy
Explanation:
Thermal and sound energy is kinetic energy.
Kinetic energy is the energy that results as a function of the motion of a body or the particles of the medium.
Sound energy is transmitted by the vibration of the particles in the air. The vibration leads to movement of the particles and hence, kinetic energy is produced.
Thermal energy originates as a result of the temperature differences in a body. This temperature difference leads to the increase in the kinetic energy of some particles which also causes vibration and motion of the particles.
Answer:
5 m
Explanation:
Speed of waves is as the product of frequency and wavelength hence expressed as s=fw where f is the frequency of waves in Hz, s is the speed in m/s and w is wavelength in meters.
Making w the subject of the formula then
Substituting 335 m/s for s and 67 Hz for f then the wavelength is
Wavelength is the distance between successive crests. Since the string is 10m, wavelengths of 5m each will be 2 and the crests will be 3.
Wavelenth=5 m
Answer:
66.053m/s
Explanation:
A = 47
B = 347
C = 19
Train moves at
(23 + A)m/s
= 23 + 47 = 60m/s
At (250.0+B) seconds
250.0+347 =
547 seconds
Distance d,
= 70 x 597
= 41790
It also moves at
(45.0 + c)
= 45 + 19
= 64m/s
Time = 800 + B
= 800 + 347
= 1147
Distance,
= 64 x 1147
= 73408m
Total distance,
= 73408 + 41790
= 115,198
Total time,
= 597 + 1147
= 1744
Average speed,
= Total distance / total time
= 115198/1174
= 66.053m/s
Answer:
Explanation:
Given data
Coefficient of performance of a residential heat pump=1.6
Electrical power P=4kW
Required
Heat Q
Solution
The rate of heat produced is given as
Substitute the given values
So
