Question

A boy pushes a 25 kg shopping cart.
a)What force is required to accelerate the cart from rest to 3.0m/s down a 15m distance?

b) What is the work done by the boy?

c) What is the kinetic energy of the shopping cart when it reaches the distance 15m?

Answer 1

Answer:

Mass (m) = 25 kg

Distance (S) = 15 m

Initial Velocity (u) = 0 m/s

Final Velocity (v) = 3 m/s

v² = u²+2aS

(3)² = 0+(2*a*15)

9 = 30a

0.3 m/s² = Acceleration

Force = Mass*Acceleration

= 25*0.3 N

= 7.5 N

Work Done = Force*Displacement

= 7.5*15 J

= 112.5 J

K.E = 1/2mv²

= 1/2*25*3*3 J

= 112.5 J

I hope this helps.