Question

How does a parachute at the end if a car helps the speeding car to slow down?

Answer 1

When a car moves, it is passing through a fluid, which is the air around us. The air actually produces a drag effect on the car but is negligible due to its shape. However, when there is a parachute in the back, it opens up when the car moves and the air tends to push into the concave side of the parachute, thus providing a backward drag force and since the parachute is connected to the car, it slows it down too. Basically, due to the shape and higher surface area of the open parachute, the air produces a more significant drag.

Answer 2

bcoz air will exert the pressure on the walls of parachute which would help the car to slow down.