Question

A motorcar of mass 1200kg is moving along a straight line with a uniform velocity of
90km/h. Its velocity is slowed down to 18km/h in 4s by an unbalanced external force.
Calculate the acceleration and the change in momentum. Also calculate the magnitude of the
force required.

step by step explanation :​

Answer 1

Answer:

-5 m/s^2 & -6000 N, respectively.

Explanation:

m = 1200 kg

u = 90 km/h = 25 m/s [1 km/h = 5/18 m/s]

v = 18 km/h = 5 m/s

t = 4s

a = (v - u)/t = (5 - 25)/4 = -20/4 = -5 m/s^2

F = ma = 1200 × -5 N = -6000 N