Question

A wagon full of manure accidentally rolls down a driveway for 5.0m while a person pushes against the wagon with a force of 420 N to bring it to a stop. What is the change in kinetic energy for the wagon?

Answer 1

Answer:

2100 J

Explanation:

Parameters given:

Force acting on the object, F = 420 N

Distance moved by object, d = 5m

The change in kinetic energy of an object is equal to the work done by a force acting on the object:

W = F * d

∆KE = F * d

∆KE = 420 * 5

∆KE = 2100 J

Answer 2

Answer:

∆KE = 2100 J

Explanation:

Given:

Force of person pushes against the wagon=  F = 420 N

Distance = d = 5.0 m

When you accelerate an object, you are doing work against inertia. It is proven that work equals the change in kinetic energy of the object.

therefore, W = ΔKE

where,

W is the work done against the resistance of inertia

ΔKE is the change in kinetic energy (Δ is Greek letter capital delta)

Also, W = F x d

∴∆KE = F x d

∆KE = 420 x 5

∆KE = 2100 J

The change in kinetic energy for the wagon is 2100 J