Calculating forces given mass, acceleration and time

Question

A 650kg car travelling 5m/s¹ NORTH EAST turns so that it is travelling 4m/s¹ NORTH in 2 seconds. Calculate the magnitude of the force required to make such a turn.

Answer 1

U is 5m/s NE; V = 4 m/s N 

 

change in velovity = vector V-U, 

                                                                                             

from the triangle of velocities that gives 3 m/s W (sorry I cannot illustrate this on this window, no graphics here !!!)

 

Assuming this change takes place uniformly, rate of change of velocity is vector (V-U)/t 3/2 m/s^2 = 1.5 m/s^2

 

From Newton's second law, force = mass * acceleration

 

Force = 650kg * 1.5 m/s^2 = 975 Newtons