Curling

is a winter sport played on ice where two teams of four players each take turns

sliding heavy granite stones towards a target area called the

"house." Team members are able to sweep the ice in front of the stone

to adjust its speed and trajectory although they are forbidden from touching

the stone. Expert and careful sweeping can lengthen the travel of the stone by

around 3 m.

A

curler pushes a 20 kg stone from rest to a speed of 3.5 m/s over a time of 2.0

s. Ignoring the force of friction (for now) and assuming a constant

acceleration, how much force must the curler apply to the stone to bring it up

to speed? Give your answer in whole numbers in Newtons. Write your answer

without units i.e., 12 N as 12.