Q2. when the driver applies the brakes of a light truck traveling 40 km/h, it skids 3 m before stopping. how far will the truck skid if it is traveling 80 km/h when the brakes are applied

12m

Explanation:

If the brake force F is constant the brakes have to do work: W = Fx, where x is the skid distance.

The work is necessary to remove the kinetic energy from the truck. It follows:

m: mass of the truck

v: velocity of the truck

The ratio between the first and the second example would be:

This expression simplifies to:

Inserting the speeds will give the ratio for  x₁/x₂:

The distance x₂ is 4 times longer then the distance x₁.

you would expect a sound wave to speed up. - b)

the answer is b

explanation: