Question

A 1580 Kg car is travelling at a speed of 15.0 m/s. What is the magnitude of the horizontal net force that is required to bring it to a halt in a distance of 50.0 m?​

Answer 1

Step-by-step explanation:

Assuming a frictionless car on a horizontal surface.

Kinematics answer

v² = u² + 2as

a = (v² - u²) / 2s

a = (0² - 15.0²) / (2(50.0)) = -2.25 m/s²

F = ma

F = 1580(2.25)

F = 3555 N

Work-Energy theorem answer

The work of the force must equal the initial kinetic energy of the car.

F(50.0) = ½(1580)15.0²

F = 3555 N