Question

An object in space is initially stationary relative
to the Earth. Then, a force begins acting
on the object, starting with a force of 0 N, and
increasing at a uniform rate until the magnitude
of the force is 58 N after the force has
acted for 25 s. The body has a mass of 10 kg.
What is the speed of the object at 25 s?

Answer 1

Area under an F vs t curve is momentum. F is linear so we get a triangle:
.5 (58) 25 = 10 v
v = 72.5