The engine of a car provides a forward force of 1240 N and the total resistive force on the car is 800N. If the mass of the car is 1220 kg, determine the distance the car has to travel from the rest before acquiring a speed of 4 m s\(^{-1}\).
- 44.0 m
-
22.2 m
- 11.1 m
- 5.5 m
The correct answer is: B
Explanation
Acceleration[a] = \(\frac{[forward - resistive]force}{mass}\)
a = \(\frac{1240-800}{1220}\) → \(\frac{440-800}{1220}\)
a = 0.36m/s\(^2\), v = 4m/s, s = ?
Second equation of motion:
s is distance
u is initial velocity
v is final velocity
a is acceleration
v\(^2\) = u\(^2\) + 2as
4\(^2\) = 0\(^2\) + 2 * 0.36 * s
16 = 0.72s
22.2m = s