Chapter 7, Problem 10TS

Students in a lab measure the speed of a steel ball launched horizontally from a tabletop to be $4.0\text{m}/\text{s}$ If it takes $0.5\text{s}$ for a ball to fall from the table to the floor below, where should they place a small piece of paper so that the ball will hit it when it lands?

To determine

The position at which a small piece of paper is placed so that a ball launched horizontally from a tabletop will hit it when it lands.

Answer to Problem 10TS

The piece of paper should be placed at a distance of 2 m from the table so that the ball will land on it.

Explanation of Solution

Given info: The horizontal velocity of the ball is $4.0\text{m}/\text{s}$ and the time taken for the ball to reach the floor from the table is $0.5\text{s}$ .

Write the expression for the horizontal distance from the table to the piece of paper.

$S=v_{x}t$

Here,

$v_x$ is the horizontal velocity

$t$ is the time taken

Substitute $4.0\text{m}/\text{s}$ for $v_x$ and $0.5\text{s}$ for $t$ in the above equation to get $S$ .

$\begin{array}{c}S=4.0\text{m}/\text{s}\times 0.5\text{s}\\ =2\text{m}\end{array}$

Conclusion:

Therefore, the piece of paper should be place at a distance of $2\text{m}$ from the table so that the ball will land on it.