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Part 3

What is the magnitude and direction of the force on the pin at the bottom of the boom?

For vertical equilibrium, the vertical forces must sum to zero.

V + 24000 newtons - 6000 newtons = 0, or

V = 6000 newtons - 24000 newtons, or

V = -18000 newtons

Therefore, the force on the pin is 18000 newtons down.

Sliding a crate

A crate is being slid to the right on a horizontal floor by pulling on a rope tied to the right side of the crate.

Width of the crate = w = 4 m

Height of the crate = h = 3 m

Coefficient of kinetic friction = u = 0..5

Attachment point of rope = d = ?

Part 1

Draw a picture of the crate showing the forces that are being exerted on the crate.

Solution:

The crate is a rectangle with the dimensions given above. There are three forces acting on the crate.

There is a downward force at the bottom center of the crate, which is the weight of the crate. Label it F1.

There is a horizontal force pointing to the left at the bottom of the crate. This is the force of friction. Label it F2.

There is a horizontal force pointing to the right on the right side of the crate that is d units above the floor. This is the force that is pulling thecrate to the right. Label it F3.

Part 2

What is the maximum value for d that allows the crate to slide without tipping over?

Compute the sum of the horizontal forces.

F3 - F2 = 0, or

F3 - m*g*u = 0, or

F3 = m*g*u

Compute the torques about the bottom right corner.

(w/2)*F1 - d*F3 = 0, or

d*F3 = (w/2)*F1, or

d*F3 = (w/2)*m*g

Substitution yields

d*m*g*u = (w/2)*m*g

Simplification yields

d*u = (w/2), or

d = (w/2)/u

Inserting values yields

d = (4/2)/0.5, or

d = 4 m

Since the height of the crate is only 3 m, it is not possible to tip it over by pulling on a rope attached to the right side of the crate.

Another crane scenario

The boom of a crane is pinned at the intersection of a horizontal floor and a vertical wall. The boom slopes toward the upper right.

A mass hangs from the top end of the boom.

The top end of the boom is connected to the vertical wall by a cable that is stretched horizontally from the wall to the boom.

Length of cable = X = 4 m

Height of cable = Y = 3 m

Mass = M = 2000 kg

The weight of the boom is negligible.

Part 1

Draw the forces acting on the boom.

Solution:

There are four forces acting on the boom:

A downward force that is attributable to the mass hanging on the top end of the boom. Label this force F1.

A force pointing to the left from the top end of the boom due to the cable. Label this force F2.

A force pointing up at the bottom end of the boom. Label this force F3.

A force pointing to the right at the bottom of the boom. Label this force F4.

Part 2

Find the tension in the cable.

Solution:

For rotational equilibrium, the sum of the torques about the bottom of the boom must be zero.

F2*Y = F1*X, or

F2*Y = M*g*X, or

F2 = (M*g*X)*/Y

Inserting numeric values yields

F2 = (2000kg*(9.8m/s^2)*4m)/3m

F2 = 26133 newtons

Therefore, the tension in the cable is equal to 26133 newtons

Part 3

Find the force pushing against the bottom end of the boom along the length of the boom. Also find the angle between that force and the floor.

Questions & Answers

Three charges q_{1}=+3\mu C, q_{2}=+6\mu C and q_{3}=+8\mu C are located at (2,0)m (0,0)m and (0,3) coordinates respectively. Find the magnitude and direction acted upon q_{2} by the two other charges.Draw the correct graphical illustration of the problem above showing the direction of all forces.
Kate Reply
To solve this problem, we need to first find the net force acting on charge q_{2}. The magnitude of the force exerted by q_{1} on q_{2} is given by F=\frac{kq_{1}q_{2}}{r^{2}} where k is the Coulomb constant, q_{1} and q_{2} are the charges of the particles, and r is the distance between them.
Muhammed
What is the direction and net electric force on q_{1}= 5µC located at (0,4)r due to charges q_{2}=7mu located at (0,0)m and q_{3}=3\mu C located at (4,0)m?
Kate Reply
what is the change in momentum of a body?
Eunice Reply
what is a capacitor?
Raymond Reply
Capacitor is a separation of opposite charges using an insulator of very small dimension between them. Capacitor is used for allowing an AC (alternating current) to pass while a DC (direct current) is blocked.
Gautam
A motor travelling at 72km/m on sighting a stop sign applying the breaks such that under constant deaccelerate in the meters of 50 metres what is the magnitude of the accelerate
Maria Reply
please solve
Sharon
8m/s²
Aishat
What is Thermodynamics
Muordit
velocity can be 72 km/h in question. 72 km/h=20 m/s, v^2=2.a.x , 20^2=2.a.50, a=4 m/s^2.
Mehmet
A boat travels due east at a speed of 40meter per seconds across a river flowing due south at 30meter per seconds. what is the resultant speed of the boat
Saheed Reply
50 m/s due south east
Someone
which has a higher temperature, 1cup of boiling water or 1teapot of boiling water which can transfer more heat 1cup of boiling water or 1 teapot of boiling water explain your . answer
Ramon Reply
I believe temperature being an intensive property does not change for any amount of boiling water whereas heat being an extensive property changes with amount/size of the system.
Someone
Scratch that
Someone
temperature for any amount of water to boil at ntp is 100⁰C (it is a state function and and intensive property) and it depends both will give same amount of heat because the surface available for heat transfer is greater in case of the kettle as well as the heat stored in it but if you talk.....
Someone
about the amount of heat stored in the system then in that case since the mass of water in the kettle is greater so more energy is required to raise the temperature b/c more molecules of water are present in the kettle
Someone
definitely of physics
Haryormhidey Reply
how many start and codon
Esrael Reply
what is field
Felix Reply
physics, biology and chemistry this is my Field
ALIYU
field is a region of space under the influence of some physical properties
Collete
what is ogarnic chemistry
WISDOM Reply
determine the slope giving that 3y+ 2x-14=0
WISDOM
Another formula for Acceleration
Belty Reply
a=v/t. a=f/m a
IHUMA
innocent
Adah
pratica A on solution of hydro chloric acid,B is a solution containing 0.5000 mole ofsodium chlorid per dm³,put A in the burret and titrate 20.00 or 25.00cm³ portion of B using melting orange as the indicator. record the deside of your burret tabulate the burret reading and calculate the average volume of acid used?
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how do lnternal energy measures
Esrael
Two bodies attract each other electrically. Do they both have to be charged? Answer the same question if the bodies repel one another.
JALLAH Reply
No. According to Isac Newtons law. this two bodies maybe you and the wall beside you. Attracting depends on the mass och each body and distance between them.
Dlovan
Are you really asking if two bodies have to be charged to be influenced by Coulombs Law?
Robert
like charges repel while unlike charges atttact
Raymond
What is specific heat capacity
Destiny Reply
Specific heat capacity is a measure of the amount of energy required to raise the temperature of a substance by one degree Celsius (or Kelvin). It is measured in Joules per kilogram per degree Celsius (J/kg°C).
AI-Robot
specific heat capacity is the amount of energy needed to raise the temperature of a substance by one degree Celsius or kelvin
ROKEEB
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Source:  OpenStax, Accessible physics concepts for blind students. OpenStax CNX. Oct 02, 2015 Download for free at https://legacy.cnx.org/content/col11294/1.36
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