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