1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
kobusy [5.1K]
3 years ago
12

A small wooden block with mass 0.750 kg is suspended from the lower end of a light cord that is 1.72 m long. The block is initia

lly at rest. A bullet with mass 0.0100 kg is fired at the block with a horizontal velocity v0. The bullet strikes the block and becomes embedded in it. After the collision the combined object swings on the end of the cord. When the block has risen a vertical height of 0.800 m, the tension in the cord is 4.86 N.
What was the initial speed v0 of the bullet?
Physics
1 answer:
Ierofanga [76]3 years ago
7 0

Answer:

v_{0}=319.2 m/s    

Explanation:

We need to use the momentum and energy conservation.

p_{0}}=p_{f}

mv_{0}=(m+M)V_{1}

Where:

  • m is the mass of bullet (m=0.01 kg)
  • M is the mass of the wooden (M=0.75 kg)
  • v(0) initial velocity of bullet
  • V(1) is the velocity of the combined object in the moment the bullet hist the block

Conservation of energy.

We have kinetic energy at first and kinetic and potential energy at the end.            

(1/2)(m+M)V_{1}^{2}=(1/2)(m+M)V_{2}^{2}+(m+M)gh

Here:

  • V(1) is the velocity of the combined at the initial position
  • h is the vertical height ( h = 0.800 m)

We can find V(2) using the definition of force at this point:

\Sigma F=(m+M)a_{c}=(m+M)(V_{2}^{2}/R)

T-(m+M)gcos(\theta)=(m+M)a_{c}=(m+M)(V_{2}^{2}/R)

cos(\theta) =(L-h)/L=(1.72-0.8)/1.72

\theta =57.66

Now, we can solve the equation to find V(2)

V_{2}=\sqrt{\frac{R*(T-(m+M)*g*cos(\theta))}{(m+M)}}

V_{2}=\sqrt{\frac{1.72*(4.86-(0.01+0.75)*9.81*cos(57.66))}{(0.01+0.75)}}

V_{2}=1.40 m/s        

Now we can find V(1) using the conservation of energy equation

(1/2)V_{1}^{2}=(1/2)V_{2}^{2}+gh

V_{1}=\sqrt{V_{2}^{2}+2gh}

V_{1}=\sqrt{1.40^{2}+2*9.81*0.8}          

V_{1}=4.20 m/s        

Finally, using the momentum equation we find v(0)

v_{0}=\frac{(m+M)V_{1}}{m}                

v_{0}=\frac{(0.01+0.75)*4.20}{0.01}

v_{0}=319.2 m/s        

I hope it helps you!

 

You might be interested in
What are three ways in which heat is transferred
Sedaia [141]

Conduction, Convection, Radiation.

Hope this helps!

-Payshence

6 0
3 years ago
A tennis ball is tossed upwards into the air with an initial velocity of +5m/s, how much time does it take for the tennis ball t
Sever21 [200]
HOPE THIS HELPS YOU!!!!!

3 0
2 years ago
Pressure can affect the density of<br><br> Solids<br> Liquids<br> Gases<br> Metals
gtnhenbr [62]

Answer;

-Gases

Explanation;

-Pressure can affect the density of gases.

-Density of gases changes with pressure and temperature because gases are compressible fluid and because they are compressible, when pressure increases molecules come closer to each other which means increase in density and when pressure drops molecules of gases become free to expand and get away from each other which density decrease.

7 0
3 years ago
A kayaker paddles at 4.0 m/s in a direction 30° south of west. He then turns and paddles at 3.7 m/s in a direction 20° west of s
user100 [1]
7.2 m/s 

49 degrees south of west

7 0
3 years ago
Read 2 more answers
Two charges of +4x10-SC and -4x10-5C are placed 1 meter apart. Using Coulomb's law, the force between them is 14.4 N.
Snowcat [4.5K]

Answer:

d. the force is reduced by one quarter to 3.6 n

Explanation:

6 0
2 years ago
Other questions:
  • You need to connect your doorbell to a battery. You should select wire that will A.accept the flow of electrons.
    11·2 answers
  • In Newtons first law of motion how is an object at rest affected
    6·1 answer
  • Will two sounds of 50 db constitute a sound of 100 db . Explain
    14·1 answer
  • A substance changes state from solid to liquid. What has happened?
    14·2 answers
  • A beaker of ice and water is placed on a hot plate. is it a physical or chemical change
    11·1 answer
  • HEY CAN ANYONE PLS ANSWER DIS!!!!!!
    6·1 answer
  • What can you infer about how traveling changed America? Support your inference with evidence from the text and your own knowledg
    11·1 answer
  • How many types of ion are formed when water splits during
    5·1 answer
  • A metre rule is used to measure a length Which reading is shown to the nearest millimetre? A 0.7 m B 0.76 m с 0.761 m D 0.7614 m
    9·1 answer
  • What is the mass of the roller coaster?
    7·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!