Chapter 3.2, Problem 16PP

(a)

To determine

The velocity of the golf ball after 2 s is $1\text{m}/\text{s}$ .

Answer to Problem 16PP

The velocity of the golf ball after 2 s is $1\text{m}/\text{s}$ .

Explanation of Solution

Given Info:

The initial speed of the golf ball is $u=2\text{m}/\text{s}$

The acceleration of the golf ball is $a=0.50\text{m}/{\text{s}}^2$ .

The time for art (a) is $t_a=2\text{s}$

The time for part (b) is $t_b=6\text{s}$

Formula Used:

The expression to calculate the velocity of the golf ball is

  $v=u-a{t}_a$

Here,

• $v$ is the velocity of the golf ball.

Calculation:

Substitute all the values in the above expression.

  $\begin{array}{c}v=2\text{m}/\text{s}-\left(0.50\text{m}/{\text{s}}^2\right)\left(2\text{s}\right)\\ =1\text{m}/\text{s}\end{array}$

Thus, the velocity of the golf ball after 2 s is $1\text{m}/\text{s}$ .

(b)

To determine

The velocity of the golf ball after 6 s is $-1\text{m}/\text{s}$ .

Answer to Problem 16PP

The velocity of the golf ball after 6 s is $-1\text{m}/\text{s}$ .

Explanation of Solution

Formula Used:

The expression to calculate the velocity of the golf ball is

  $v=u-a{t}_b$

Calculation:

Substitute all the values in the above expression.

  $\begin{array}{c}v=2\text{m}/\text{s}-\left(0.50\text{m}/{\text{s}}^2\right)\left(6\text{s}\right)\\ =-1\text{m}/\text{s}\end{array}$

Thus, the velocity of the golf ball after 2 s is $-1\text{m}/\text{s}$ .

(c)

To determine

Description of the motion of the golf ball and the motion diagram.

Answer to Problem 16PP

The motion of the golf ball is continuously decelerating motion and the motion diagram is shown in figure (1).

Explanation of Solution

Introduction:

The acceleration is described by the slope of the graph. As the acceleration slows down the golf ball, the slope of the motion diagram is negative.

The golf ball is moving with the velocity and it slows down due to deceleration. The velocity of the golf ball becomes $1\text{m}/\text{s}$ after 2 s and after 6 s it becomes $-1\text{m}/\text{s}$ .

  

Figure (1)

Conclusion:

Thus, the motion of the golf ball is continuously decelerating motion and the motion diagram is shown in figure (1).