Rolling of the eyes. The person is either vexed or frustrated.
Mass of the system is 25.2 kg
Calculation:
F=ma
m = F/a where a = m/t^2
a=2.3/(1.3)^2 = 1.36 m/s^2
m=34.3/1.36
m=25.2 Kg
Answer:
The force needed to slow down the car is, F = 67.5 N
Explanation:
Given data,
The mass of the car, m = 15 kg
The initial velocity of the car, V = 60 m/s
The final velocity of the car, v = 15 m/s
The time period of deceleration, t = 10 s
The difference in the momentum of the car is,
mV - mv = 15(60 - 15)
= 675 kg m/s
The rate of change in momentum of the car gives the force acting on it.
F = (mV - mu) / t
Substituting the values,
F = 675 / 10
= 67.5 N
Hence, the force needed to slow down the car is, F = 67.5 N