A motorcycle of weight 1.9 kN accelerates from 0 to 87.4 km/h in 5.2 s. What are the magnitudes of (a) the constant acceleration and (b) the net force causing the acceleration?

(a) 4.67 m/s²

(b) 905.42 N

Explanation:

Given:

Weight, w = 1.9 kN

       weight = mass × acceleration due to gravity

           1.9 kN = mass × 9.8 m/s²

             mass =

                       = 193.88 kg

Initial velocity, u = 0 m/s

Final velocity, v = 87.4 km/h

converting to m/s = = 24.28 m/s

Time, t = 5.2 s

From equation of motion;

                      v = u + at

                    24.28 = 0 + 5.2a

                   5.2a = 24.28

                        a = 4.67 m/s²

(b) From Netwon's second law of motion, the force acting on a body is equal to the product of the mass and acceleration experienced by the body.

                       F = mass × acceleration

                       F = 193.88 × 4.67

                      F = 905.42 N