Question

At a construction site, a 1.50-kg brick is dropped from rest and hits the ground at a speed of 26.0 m/s. Assuming air resistance can be ignored, calculate the gravitational potential energy of the brick before it was dropped.

Answer 1

The gravitational potential energy of the brick before it was dropped is 58.8 joules.

Step-by-step explanation:

The gravitational potential energy (U) of an object near the Earth's surface is given by the formula

ℎ

U=mgh, where

m is the mass of the object,

g is the acceleration due to gravity, and

ℎ is the height.

In this scenario, the brick is dropped from rest, so its initial velocity (vi) is 0 m/s. The final velocity (vf ) just before hitting the ground is given as 26.0 m/s. Using the kinematic equation2=2+2ℎv f2 =vi2 +2gh, where

g is the acceleration due to gravity, and rearranging for

ℎ, we can find the height from which the brick fell.

Once the height (ℎ) is determined, we can use the gravitational potential energy formula to find the potential energy before dropping:

U=mgh

This calculation requires knowledge of the acceleration due to gravity, which is approximately

9.8m/s near the Earth's surface. The specific calculation is dependent on the height determined from the kinematic equation.