physicsspeed
posted by Damon on .
i need help with this one
thanks
A particle starts from rest and is acted on by a net force that does work at a rate that is proportional to the time t. The speed of the particle is proportional to:
a. sq. root t
b. t
c. t^2
d.1/sq. root t
e. 1/t
Work done is proportional to the integral of a constant times t. That means the work done is proportional to t^2. It will equal the final kinetic energy, which is proportional to v^2. Therefore v^2 is proportional to t^2, and v must be proportional to t.

i choose answer d.