How much time would be required to stop a 2,000kg car that is moving at 80.0km/hr if the breaking force is?

Question

how do you solve and what formula would you use?

Answer 1

First of all, you have not provide us with the braking force. Therefore, it is hard to give you the exact number. Perhaps I could provide you with a general description. Let the braking force be F.

1) Calculate the deceleration of the car with braking force,
Since F=ma,
a= -F/m = -F/2000 (negative sign to show deceleration)

2) To stop a car, the following equation is used:
a=(v-u)/t where v= final velocity, u=initial velocity and t=time

Convert u from km/h to m/s, 80km/h is 22.222m/s,
Thus, a= -22.222/t

3) Since a=-F/2000 and a=-22.222/t,
-F/2000= -22.222/t
Hence, t= 44,444/F

Answer 2

If the body is moving at a velocity v1 and a deceleration -a (the minus sign indicates deceleration) is applied to it, the final velocity after a time t is given by the equation,

v2 = v1 - at and if it has to stop, v2 has to be zero and so,

v1 - at = 0 or t = v1 / a

Force is mass X acceleration. In your question, the braking force (it is not breaking force, we don't want the car to break) is not specified, but if you know the force, divide it by the mass of the car. That gives the negative acceleration or deceleration.

You need to convert 80 km/hr to metres per second and then use the formula showed above.

Answer 3

You haven't given us the breaking force, and it looks as though it should be given, let's say:
breaking force = F.
F = ma
a = F/m = F/2000
v = at
t = v/a = 80/(F/2000) = 80x2000/F

Answer 4

Have a play around with the classic F=ma

a=(change in velocity)/(change in time)
m = mass

Answer 5

use first formula F=ma and then a=v-u/t