Answer:
Explanation:
When an object strikes the ground, the potential energy of the rock gets converted to the kinetic energy.
A rock is dropped from a distance above the surface of the earth and is observed to have kinetic energy when it hits the ground.
For another rock, It is dropped from twice the height above the earth’s surface and has kinetic energy when it hits.
For the first rock, ..............(1)
For the second rock, ..............(2)
Dividing equation (2) by (1) we get :
Hence, this is the required solution.
Answer:
57 N
Explanation:
Draw a free body diagram. There are three forces:
Weight force mg pulling down.
Normal force N pushing up.
Friction force F pushing horizontally.
Sum of the forces in the y direction:
∑F = ma
N − mg = 0
N = mg
Friction force is the product of normal force and coefficient of friction:
F = Nμ
F = mgμ
F = (65 kg) (9.8 m/s²) (0.09)
F = 57.3 N
Rounded, the friction force is 57 N.
Answer:
Explanation:
velocity of source, Vs = 114 m/s
original frequency, f = 3.65 kHz
velocity of observer , Vo = 0 m/s
velocity of sound, v = 334 m/s
let the frequency is f'.
The formula for the doppler effect is given by
where, v is the velocity of sound.
f' = 5.54 kHz
Answer:
Explanation:
As we know that there is no external horizontal force on the cannon ball + performer
So here total momentum of the system must be conserved
so we will have
now from above equation we have