What is the net force?

Question

This is a Q in my science textbook, and I don't know how to do it. So can someone help me on this problem? Thanks in advance. :D

"An experiment measures the speed of a 250 kg motorcycle every 2 sec. The motorcycle moves in a straight line. What is the net force acting on the motorcycle?"

Chart

Speed: 0; 5; 10; 15; 20 m/s

Time: 0; 2; 4; 6; 8 sec.

I really don't understand this problem, so please help if you can.

Answer 1

force is mass times acceleration : F = m*a

acceleration is the rate of change of speed with respect to time, so in this case it's (20-0) divided by (8-0), which is 2.5.

so net force is F=250*2.5

Answer 2

the vector that equals the cross product of all of the forces that are exerted upon it

Answer 3

Starting with F = m a, all you have to do is find the force.

(Force = mass x acceleration)

Every two seconds, the speed is increasing by 5m/s.  So the acceleration is 2.5 m/s^2

Mass = 250kg

So, F = 250 x 2.5 = 625 kg-m/s^2, or 625 Newtons