Question

an object is thrown horizontally off a cliff with an initial velocity of 5.0 meters per second. the object strikes the ground 3.0 seconds later. how far from the base of the cliff

Answer 1

You know that the formula for finding horizontal displacement is; 

s=uₓt 
s=(5 m/s)(3s) 
s=15 m

Therefore, the ball travelled 15 m. 

Hope I helped :) 

Answer 2

The object will strike the ground at a distance of $\boxed{15\text{ m}}$ from the base of the cliff.

Further explanation:

This is a problem of projectile motion. When an object is thrown horizontally from a certain height, the object moves both in X and Y direction under the action of the acceleration due to gravity.

Given:

The initial velocity with which an object is thrown horizontally is $5.0\text{ m/s}$.

The object strikes the ground $3.0\text{ s}$ later so the total time of flight is $3.0\text{ s}$.

Concept:

First we choose the coordinate axis.

So let’s assume east direction as the positive X axis and vertical upward direction as the positive Y axis.

During the whole flight object is subjected to a downward acceleration $g$. In horizontal direction external force on the object is zero so acceleration in X direction will be zero.

Analyze the motion of object in both X and Y direction:

In X direction,

${a_x}=0\\{u_x}=5.0\,{\text{m/s}}$

Let the distance traveled by an object in X-direction is ${S_{\text{x}}}$.

Acceleration is defined as the rate of change of velocity. Here, in X direction the acceleration is zero; therefore velocity of object will remain same in X direction throughout the motion.

Use the second equation of motion:

${S_{\text{x}}}={u_{\text{x}}}t+\dfrac{1}{2}{a_{\text{x}}}{t^2}$

Substitute $5.0\,{\text{m/s}}$ for ${u_x}$, $3\text{ s}$ for $t$ and $0$ for ${a_x}$ in the above expression.

$\begin{aligned}{S_{\text{x}}}&=\left( {5.0\,{\text{m/s}}} \right)\left( {3\,{\text{s}}} \right)+\frac{1}{2}\left( 0 \right){t^2}\\&=15.0\,{\text{m}}\\\end{aligned}$

Thus, the object will strike the ground at a distance of $\boxed{15\text{ m}}$ from the base of the cliff.

Learn More:

1. A 30kg box being pulled across a carpeted floor brainly.com/question/7031524

2. During soccer practice, maya kicked a soccer ball at 37 degree brainly.com/question/11023695

3. Conservation of momentum during collision brainly.com/question/9484203

Answer Details:

Grade: High School

Subject: Physics

Chapter: Projectile motion

Keywords:

object, horizontally, thrown, cliff, height, initial velocity, strikes, ground, base, 5m/s, 3 sec, distance, acceleration due to gravity, X direction, Y-direction.