contestada

A 10.0 kg bowling ball is moving at 3.2 m/s. A net force of 20 N is constantly applied on the block in
the direction of its movement, until it has moved 10 m.

a) What is the net work done on the block?

b) what is the final velocity of the block?

Respuesta :

MathPhys

Answer:

a) 200 J

b) 7.1 m/s

Explanation:

Work is equal to the force times the distance. From work-energy theorem, the work done on an object is equal to the change in its kinetic energy, which is equal to half the mass times the square of the speed.

a) W = Fd

W = (20 N) (10 m)

W = 200 J

b) W = ΔKE

W = ½ mv² − ½ mv₀²

W = ½ m (v² − v₀²)

2W / m = v² − v₀²

v² = v₀² + 2W / m

v² = (3.2 m/s)² + 2 (200 J) / (10.0 kg)

v² = 50.24 m²/s²

v = 7.1 m/s