How many values must a 1-D<br> motion problem give you in<br> order to solve it?

A ball of mass 4.5 kg moving with speed of 2.2 m/s in the +x-direction hits a wall and bounces back with the same speed in the x

Levart [38]

Answer:

The change of the momentum of the ball is $-19.8\, \frac{mkg}{s}$

Explanation:

We should find $\varDelta\overrightarrow{p}=\overrightarrow{p_{f}}-\overrightarrow{p_{i}}$ (1)with $\overrightarrow{p_{i}}$ the initial momentum and $\overrightarrow{p_{f}}$ the final momentum. Linear momentum is defined as $\overrightarrow{p}=m\overrightarrow{v}$ , using that on (1):

$\varDelta\overrightarrow{p}=m \overrightarrow{v_{f}}-m \overrightarrow{v_{i}}$ (2)

It's important to note that momentum and velocity are vectors and direction matters, so if +x direction is the direction towards the wall and the -x direction away the wall $\overrightarrow{v_{i}}=+2.2\, \frac{m}{s}$ and $\overrightarrow{v_{f}}=-2.2\, \frac{m}{s}$ so (2) becomes:

$\varDelta\overrightarrow{p}=m(-2.2- (+2.2))=-(4.5)(4.4)$

$\varDelta\overrightarrow{p}=-19.8\, \frac{mkg}{s}$

8 0

3 years ago

Calculate the change in entropy that occurs in the system when 3.10 mole of isopropyl alcohol (C3H8O) melts at its melting point

ozzi

Answer:

3.10 mole of C3H8O change in entropy is 89.54 J/K

Explanation:

Given data

mole = 3.10 moles

temperature = -89.5∘C = -89 + 273 = 183.5 K

ΔH∘fus = 5.37 kJ/mol = 5.3 ×10^3 J/mol

to find out

change in entropy

solution

we know change in entropy is ΔH∘fus / melting point

put these value so we get change in entropy that is

change in entropy 5.3 ×10^3 / 183.5

change in entropy is 28.88 J/mol-K

so we say 1 mole of C3H8O change in entropy is 28.88 J/mol-K

and for the 3.10 mole of C3H8O change in entropy is 3.10 ×28.88 J/K

3.10 mole of C3H8O change in entropy is 89.54 J/K

4 0

3 years ago

Read 2 more answers

What is the minimum energy required to lift an object weighing 200 Newtons at a height of 20 meters?

lakkis [162]

Work = force x distance

200 Newtons x 20 meters

= 4,000 Joules

4 0

3 years ago

A freight train rolls along a track with considerable momentum. If it were to roll at the same speed but had twice as much mass,

fomenos

Answer:

The momentum would be doubled

Explanation:

The magnitude of the momentum of the freight train is given by:

$p=mv$

where

m is the mass of the train

v is its speed

In this problem, we have that the speed of the train is unchanged, while the mass of the train is doubled:

$m'=2m$

therefore, the new momentum is

$p'=m'v=(2m)v=2(mv)=2p$

so, the momentum has also doubled.

7 0

3 years ago

A woman holds a book by placing it between her hands such that she presses at right angles to the front and back covers. The boo

In-s [12.5K]

Answer:

Explanation:

In order to solve this problem we need to make a free body diagram of the book and the forces that interact on it. In the picture below you can see the free body diagram with these forces.

The person holding the book is compressing it with his hands, thus exerting a couple of forces of equal magnitude and opposite direction with value F.

Now the key to solving this problem is to analyze the equilibrium condition (Newton's third law) on the x & y axes.

To find the weight of the book we simply multiply the mass of the book by gravity.

W = m*g

W = 1.3[kg] * 9.81[m/s^2]

W = 12.75 [N]

7 0

3 years ago

How many values must a 1-D motion problem give you in order to solve it?