Question

A mass of 5KG is on top of a building of heights 10M calculate its potential energy the mass then falls at a speed of 8M/S in 4 seconds find its KE and momentum P what is the force and impulse the mass transfers to the ground

Answer 1

Potential energy:

$$E=mgh=(5)(9.8)(10)=490\ J$$

$$KE=0.5mv^2=0.5(5)(8)^2=160\ j$$

$$P=mv=(5)(8)=40\frac{kgm}{s}$$

The impulse the mass transfers to the ground:

$$I=P=40\frac{kgm}{s}$$

The force:

$$F=\frac{I}{t}=\frac{40}{4}=10\ N$$