A bicycle and its rider together have a mass of 61 kg. If the bicycle's speed is 13 m/s, how much force is needed to bring it to a stop in 6s?

Question

I need help with my physical science class

Answer 1

 Force = mass x acceleration

 

              acceleration  =  ( Final velocity - initial velocity)/time

 

                                  =  ( 0  - 13)/6 = -13/6

 

 

Force = 61 kg * -13/6  meters per second-squared = -132 and 1/6 newtons of force opposite the direction

Answer 2

F = ma

 

a = Δv/Δt = [(0 - 13) m/s ] / (6 s) = -2.167 m/s²

 

F = ma = (61 kg)(-2.167 m/s²) ≅ -132.2 N

 

The minus sign means the applied force is opposite the direction of motion.