i the conveyor belt takes 54 seconds to move gravel from the bottom of the conveyor belt to the tope at a rate of 3 feet per second, how high does the conveyor belt lift the gravel?

Usually conveyors are at an angle with the horizontal. Here for lack of more information, we assume that the conveyor is vertical (using pouches) to carry the gravel, or the 3 feet per second is measured vertically.

3 feet/second * 54 seconds
= 3*54 feet
=162 feet

To find the height the conveyor belt lifts the gravel, we need to multiply the rate at which it moves, which is 3 feet per second, by the time it takes to reach the top, which is 54 seconds. This will give us the total distance traveled by the gravel.

Height = Rate × Time

Height = 3 feet per second × 54 seconds

Height = 162 feet

Therefore, the conveyor belt lifts the gravel to a height of 162 feet.