Question

Question: If a baseball pitcher throws a fastball at a horizontal speed of 160 Km/hr,how long does the ball take to reach homeplate 18.4 maway?

Short answer

The time taken by ball to reach home plate is$414\text{m/s}$ .

Step-by-step solution

Given data

The speed of the ball is$160\text{km/h}$ .

The distance of the plate is$18.4\text{m}$ .

Understanding the speed of an object.

The speed of an object is defined as the rate of change of distance with time. It is a scalar quantity.

The expression for the speed is given as follows:

$\text{Distance=Speed×Timeinterval}$ … (i)

Determination of time taken by ball to reach the plate. 

First, convert the speed of the ball from $\text{km/h}$to$\text{m/s}$ .

The speed of the ball can be written as,

$$\begin{gathered} \text{Speed=160km/h} \\ =160\times \frac{5}{18}\text{m/s} \\ =44.44\text{m/s} \end{gathered}$$

From equation (i), the time taken by ball is calculated as follows:

role="math" localid="1650526041222" $$\begin{gathered} \text{Timeinterval=}\frac{\text{Distance}}{\text{Speed}} \\ \text{=}\frac{18.4\text{m}}{44.44\text{m/s}} \\ =\text{0.414s} \\ =414\text{ms} \end{gathered}$$

Thus, the time taken by ball to reach home plate is$414\text{ms}$.