Answer:
B) 12 m
Explanation:
Gravitational potential energy is:
PE = mgh
Given PE = 5997.6 J, and m = 51 kg:
5997.6 J = (51 kg) (9.8 m/s²) h
h = 12 m
Answer:
Friction force on the bullet is 58.7 N opposite to its velocity
Explanation:
As we know that initial speed of the bullet is 55 m/s
after travelling into the sand bag by distance d = 1.34 m it comes to rest
so final speed
now we can use kinematics top find the acceleration of the bullet
so we have
now by Newton's II law we know that
so we have
Answer:
Option (c) is correct.
Explanation:
The apparent change in the frequency of light due to the relative motion between the source and the observer is called Doppler's effect.
When the source is moving towards the observer which is at rest, the apparent frequency increases and if the observer is moving away the frequency of sound decreases.
It occurs for both light and sound.
So, to explain the blue shift of light in the universe is due to the Doppler's effect of light.
