Speed is equal to distance traveled divided by the time. So it's 3.5 m/s
The centripetal force acts upon an object moving in a circle at constant speed. The centripetal force acts perpendicular to the direction of motion , the speed of object will remain constant.
14.136 J as shown on the photo with two thought processes but overall same calculation
Answer:
The number of turns in the solenoid is 230.
Explanation:
Given that,
Rate of change of current, 
Induced emf, 
Current, I = 1.5 A
Magnetic flux, 
The induced emf through the solenoid is given by :

or
........(1)
The self inductance of the solenoid is given by :
.........(2)
From equation (1) and (2) we get :

N is the number of turns in the solenoid


N = 229.28 turns
or
N = 230 turns
So, the number of turns in the solenoid is 230. Hence, this is the required solution.
So power is equal to work over time and work is force times distance, you do 5 times 3 and get 15 dividing by 2 gives us 7.5 W answer c