Question
A scooter of mass 120 kg is moving with a uniform velocity of 108 km/h. The force required to stop the vehicle in 10 s is
- 720 N
- 180 N
- 360 N
- 216 N
Answer
360 N
Explanation
We can start by calculating the initial momentum of the scooter, which is given by:
p = m × v
where p is momentum, m is mass, and v is velocity.
Substituting the given values, we get:
p = 120× 108 ×{5 \over 18 }
To bring the scooter to a stop in 10 s, a net force must be applied in the opposite direction of motion. The magnitude of this force can be found using the equation:
F = Δp / t
where F is force, Δp is the change in momentum, and t is the time interval over which the change occurs.
Since the scooter comes to a stop, the final momentum is zero. Therefore, the change in momentum is equal to the initial momentum. Substituting the values, we get:
F = 36000 / 10 s = 3600 N