1. a crane lifts a 75kg mass a height of 8 m. calculate the gravitational potential energy
gained by the mass:

GP.E = 5880 j

Explanation:

Given data:

Mass = 75 kg

height = 8 m

Potential energy = ?

Solution:

The formula for gravitational potential energy is

GPE = mgh

m = mass in kilogram

g = acceleration due to gravity

h = height in meter above the ground

Formula:

GP.E = mgh

Now we will put the values in formula.

g = 9.8 m/s²

GP.E = 75 Kg × 9.8 m/s²× 8 m

GP.E = 5880 Kg.m²/s²

Kg.m²/s² = j

GP.E = 5880 j

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).