A 4 kg car with frictionless wheels is on a ramp that makes a 25° angle with the horizontal. The car is connected to a 1 kg mass by a string that passes over a frictionless pulley.

What is the acceleration of the car?

Refer to the diagram shown below.

W₁ = (4 kg) * (9.8 m/s²) = 39.2 N

W₂ = (1 kg) * (9.8 m/s²) = 9.8 N

The normal reaction on the 4-kg mass is

N = (39.2 N) * cos (25°) = 35.5273 N

The force acting down the inclined plane due to the weight is

F = (39.2 N) * sin (25°) = 16.5666 N

The net force that accelerates the 4-kg mass at a m/²s down the plane is

F - W₂ = (4 kg) * (a m/s²)

4a = 16.5666 - 9.8

a = 1.6917 m/s²

Answer: 1.69 m/s² (nearest hundredth)