Question

a man pushes a car with a force of 127.5n along a straight horizontal road.he manages to increase the speed of the car from 1 m/s to 2.8 m/s in 12 seconds. find the mass of the car. figure out acceleration first.

Answer 1

In order to determine the mass of the car, you first calculate the acceleration of the car, by using the following formula:

`a=(v_2-v_1)/(\Delta t)`

where:

v2: final speed of the car = 2.8 m/s

v1: initial speed of the car = 1 m/s

Δt: time interval = 12 s

You replace the previoues values into th formula for the acceleration:

`a=(2.8m/s-1.0m/s)/(12s)=0.15(m)/(s^2)`

Next, you the Newton's second law to find the mass of the car. You proceed as follow;

`F=ma`

where:

m: mass of the car = ?

a: acceleration of the car = 0.15m/s²

F: force exerted on the car by the man = 127.5N

You solve for m in the formula for F, and you replace the values of the other parameters to obtain m, just as follow:

Hence, the mass of the car is 850kg