Chapter 1.7, Problem 20P

A)

Interpretation Introduction

Interpretation:

The force of gravity acting on the box has to be determined.

Concept introduction:

The force of gravity acting on the box:

$F=M\times a$

Here, mass is M and acceleration is a.

B)

Interpretation Introduction

Interpretation:

The work required to lift the box from the ground to roof of the building.

Concept introduction:

The work required to lift the box.

$W=F\times d$

Here, force is F and distance is d.

C)

Interpretation Introduction

Interpretation:

The potential energy of the box when it is on the roof of the building.

Concept introduction:

The potential energy of the box

$\text{P}\text{.E}=M\times h\times g$

Here, gravity is g and height of building is h.

D)

Interpretation Introduction

Interpretation:

The velocity and kinetic energy of box when it hits the road.

Concept introduction:

The kinetic energy of the box when its hits the road.

$\text{K}\text{.E}=\frac{1}{2}M{v}^2$

Here, velocity is v.