Free fall is a special case of motion with constant acceleration, because acceleration due to gravity is always constant and downward. For example, when a ball is thrown up in the air, the ball's velocity is initially upward.
Answer:
67.44 V
Explanation:
Number of turns N =123
Radius = 2.41 cm =0.0241 m
The magnetic field strength increases from 50.9 T to 96.3 T so change in magnetic field dB = 96.3-50.9=45.4 T
Time interval dt = 0.151 sec
We know that the induced emf 
Area 
Putting all these values in emf equation
here negative sign indicates that it opposes the cause due to which it is produced
Explanation:
Given that,
A girl pushes her little brother on his sled with a force of 200. N for 850. m
We need to find the work done by the force of friction acting on the sled. The force of friction is 200 N
Net force = 200 N - 200 N = 0
Work done = 0
If force of friction is 300 N.
Net force = 300 N - 200 N = 100 N
The work done by a force is given by :
W = Fd
Put values,
W = 100 × 850
W = 85000 J
Hence, this is the required solution.
Speed is distance divided by time (s = d/t)