Download the App!

Get 24/7 study help with the Numerade app for iOS and Android! Enter your email for an invite.

Get the answer to your homework problem.

Try Numerade free for 7 days

Like

Report

$\cdot$ $\cdot$ You throw a 20 $\mathrm{N}$ rock into the air from ground level andobserve that, when it is 15.0 $\mathrm{m}$ high, it is traveling upward at25.0 $\mathrm{m} / \mathrm{s} .$ Use the work-energy principle to find (a) the rock'sspeed just as it left the ground and (b) the maximum height therock will reach.

a) 30.3 $\mathrm{m} / \mathrm{s}$b) 46.8 $\mathrm{m}$

Physics 101 Mechanics

Chapter 7

Work and Energ

Physics Basics

Applying Newton's Laws

Kinetic Energy

Potential Energy

Energy Conservation

University of Michigan - Ann Arbor

Simon Fraser University

McMaster University

Lectures

03:47

In physics, the kinetic en…

04:05

In physics, a conservative…

01:59

You throw a $20-\mathrm{N}…

07:23

You throw a 3.00-N rock ve…

01:37

A 2.00-kg rock is released…

04:48

A batter hits a baseball w…

02:46

A dynamite blast at a quar…

05:22

A stone with a weight of 5…

01:48

Bob can throw a $500 \math…

0:00

A 0.26-kg rock is thrown v…

05:26

As a rock of mass 4 kg dro…

01:13

As a rock of mass 4 $\math…

02:38

A 2.0 -kg rock that is ini…

03:48

A 20 -kg rock is on the ed…

05:13

A 1.50 kg snowball is fire…

04:29

A ball is thrown verticall…

03:06

(II) A 1.60-m-tall person …

03:57

A small rock is thrown ver…

02:21

(II) A $1.60-\mathrm{m}$ t…

07:13

A rock is thrown verticall…

03:28

01:03

A 2 kg rock is dropped off…

Now we are going to solve question number 21 point in this question. It is given that i is told for an object is thrown upwards in the air from the ground level. Now, first of a week, we will draw the situation. This is the ground level and the rock is thrown upwards, it attains a height at, and the maximum height is capital from the ground level. At the maximum height the velocity is 0 and that height h, the velocity is v, let the initial velocity of tronger. Be? U, in the question we are given the weight of the rock s, w equals 20 newton's. That'S the mass of the row is 2 g. We take the value of acceleration due to gravity as 10 meter per second square. The acceleration due to gravity is acting downwards and the rock is moving upwards against the gravitational force. The height attained by the row is given as 15 meters and the velocity at this height is v equals 25 meter per second. In the first part of the question we have to find the initial velocity of tone by the work energy principle. If a resistance is neglected, then the initial kinetic energy of throwing the stone is equal to the total energy at height h. Thus we can write m. U square is equal to the gravitational potential energy attached, plus the kinetic energy substituting the given values we get 2 square is equal to 2 into 10 into 15, plus h, 20 pi square. Solving this expression. We get the initial velocity. U s! 30.4 meters per second, the resistance is neglected. Then we cannot apply the work energy principle and we have to consider the work that by a resistance also, we do not need that concept here. In the second part of the question we have to find the maximum height attained by the stone. The maximum height is capital h here again using work energy principle, the initial kinetic energy of the stone half m: u square is equal to maximum gravitational potential energy attained by the stone at maximum height plus kinetic energy. At that height, which is 0 because a stone can not go further upwards from the maximum height nt, so again, sustinere m has canceled on both sides to 30.4 square is equal to 102 h. This capital h or maximum height is 47 meters. Approximately. This is the maximum height.

View More Answers From This Book

Find Another Textbook

Numerade Educator

In physics, the kinetic energy of an object is the energy which it possesses…

In physics, a conservative force is a force that is path-independent, meanin…

03:16

$\bullet($ a) The density (mass divided by volume) of water is 1.00 $\mathrm…

04:03

$\bullet$$\bullet \mathrm{A} 75,600 \mathrm{N}$ spaceship comes in for a ver…

02:36

A ladybug starts at the center of a 12 -in.-diameter turntable and crawls in…

04:19

Accident analysis. Two cars collide at an intersection. Car $A$, with a mass…

02:59

What diameter must a copper wire have if its resistance is to be the same as…

01:40

$\bullet$ How many nanoseconds does it take light to travel 1.00 $\mathrm{ft…

04:25

$\bullet$ How long would it take you to walk to the moon, and how many steps…

03:20

A copper transmission cable 100 $\mathrm{km}$ long and 10.0 $\mathrm{cm}$ in…

04:43

What is the period of revolution of a satellite with mass $m$ that orbits th…

01:05

$\bullet$ How much blood in a heartbeat? A typical human contains 5.0 $\math…