Question

A car is stopped for a traffic signal. When the light turns green, the car accelerates, increasing its speed from 0 to 5.30 m/s in 0.842 s. What are the magnitudes of the linear impulse and the average total force experienced by a 60.0 kg passenger in the car during the time the car accelerates?

linear impulse _______ kg·m/s
average force _______ N

Answer 1

a)318 b) 377.7

Step-by-step explanation:

Since the passenger is in the bus, the passenger has the same acceleration with the bus and also the same speed with the car

Linear impulse = mass * change in velocity (Vf - Vi)

Vf = final velocity and Vi = initial velocity

Where m(mass) is the mass of the passenger,

Linear impulse = 60kg * (5.30 - 0) = 318 kgm/s

b) F( average) = m * acceleration

Acceleration = Vf - Vi/ t = 5.30 - 0 / 0.842

a = 6.295m/s2

F = 60 * 6.295

F = 377.7N

Answer 2

average force 377.67 N

linear impulse 318 kg.m/s

Step-by-step explanation:

For the speed to increase from 0 to 5.3 m/s in 0.842 seconds. The constant acceleration is:

`a = (\Deltav)/(t) = (5.3 - 0)/(0.842) = 6.3 m/s^2`

So the average force acting on the 60kg passenger is (according to Newton's 2nd law):

`F = ma = 60*6.3 = 377.67 N`

The linear impulse experience by passenger within these seconds is

`P = F\Deltat = 377.67*0.842 = 318 kg.m/s`