a) To find the deceleration, we can use the formula F = ma, where F is the force, m is the mass, and a is the acceleration.
Given:
Mass (m) = 1000 kg
Force (F) = 5000 N
Using the formula: F = ma
5000 = 1000 * a
Divide both sides by 1000:
a = 5000 / 1000
a = 5 m/s²
Therefore, the deceleration of the car is 5 m/s².
b) To find the time it takes to stop the car, we can use the formula v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time.
Given:
Initial velocity (u) = 20 m/s
Final velocity (v) = 0 m/s
Acceleration (a) = -5 m/s² (negative because it is deceleration)
Using the formula: v = u + at
0 = 20 + (-5)t
Rearrange the equation:
5t = 20
Divide both sides by 5:
t = 20 / 5
t = 4 seconds
Therefore, it takes 4 seconds to stop the car.
7. A car has a mass of 1000 kg and is travelling
at 20 m/s.
The brakes then exert a steady force of 5000 N.
a) What is the deceleration?
b) How long does it take to stop the car?
1 answer