Question

. A 1770-kg car is traveling with a speed of 19.9 m/s. What is the magnitude of the horizontal net force that is required to bring the car to a halt in a distance of 42.1 m?

Answer 1

Given, Mass of the Car = m = 1770 kg

Speed of the car = u = 19.9 m/s

Distance to be travelled = s= 42.1 m

Final velocity of the car = V = 0 m/s

Let, a = deceleration of the car We know that,

V^2-u^2 = 2*a*s ==> 0-19.9^2 = 2*a*42.1

a = -4.70 m/s2 (Negative Sign Indicates Deceleration of the car)

Therefore, Force required = F = m*a

F = - 1770 * 4.70

F = - 8319 N (Negative sign indicates that force is to be applied opposite to the intial velocity direction of the car)

distance of 42.1 m is 8319 N

Hence the answer is 8319 N

I hope help you......