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Quiz2
Name
<ÿ'ÿ" period
date
1. The box on thejfi'ictionless ramp is helÿat rely the tension force. The mass of the
box is 30 kg, What is the value of the tNNf0n force?
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What is the value of the normal force?
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2, A man pulls a 50 kg box atconÿstanÿcross the floor. He applies a 200 N force at
an angle of 30°.
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(a) Sum the forces in the x-direction. What is the value of the frictional force
opposing the motion?
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(b) Sum the forces in the y-direction, What is the value of the normal force?
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3 A person lÿulls)oEa.30kg desk with a 212 N force acting at 45° angle above the horizontal,
The desk doe"w'fioÿ budgeÿ")
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(a) Draw a force diagram for the desk,
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(b) Write the net force equation in the x-direction and calculate friction force,
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(c) Write the net force equation which describes the forces which act in the y-direction,
Calculate the normal force.
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(1) A 0.150 kg baseball is thrown upward with an initial speed of 20 m/s.
(a) What is the force on the ball when it reaches half of its maximum height? (neglect air)
(b) What is the force on the ball when it reaches its peak?
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(2) The diagram on the right shows the two
forces acting on a sky diver as she leaves
the plane to when she reaches terminal
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velocity. Fill in the missing forces (give
exact values) and/or the net force as
required in the space provided. She
f
weighs 450 N.
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(3) A climber of mass 70 kg slides down a rope while holding on tightly to produce a frictional
force of 400 N.
(a) What is the weight of the climber?
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(b) What is the net force on the climber?
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(c) He now holds the rope more tightly so he falls at constant speed. What is the value of
the frictional force now?
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(4) What is the g on the surface of Mars, which has--of 3.38x10S m and amass of
6.42x 102ÿ kg?
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(5) A yard man drags a dead tree across the lawn by a rope. He exerts a force of 120 N along the
rope. The rope makes a 60o angle with the ground. Calculate the horizontal and vertical
components
of
the
force
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(6) A 25 kg box rests on an inclined plan; which makes a 200 angle with the horizontal.
(a) Calculate the force that tends to make the box slide down the incline.
(b) Calcÿdlÿ@(ÿforce the box exerts perpendicular to'theÿlane.
(7) Find the resultant of a eu ÿ,ÿ.zorce and a ÿu ±'ÿ force maÿ act at right angles to each other.
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(8) Wthe resukant from question 7 was acting on an object, what force would cause the object to
return to static equilibrium?
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Find the resultant of a 40 N force and a 30 N force that act at 200 to each other. What would
decreasing that angle do to the resultant?
(10) A boat being towed through a canal by means of ropes which make a 45o angle to each
other. If a force of 75 N is applied to each rope, what is the resultant force pulling the boat
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(11) If all forces are part of an action-reaction pair, that are equal and opposite, how does
anything ever move?
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Horse and Cart Problem
The cart and rider have a combined mass of 150 kg.
The horse has a mass of 230 kg.
The horse pulls on the cart with 75 Newtons of force.
1. Draw and label a force diagram for the cart to the left of the picture and for the horse to the right
of the picture. Add quantitative values for as many forces as possible.
2, What is a possible numerical value for how hard the cart pulls back on the horse? Explain why,
3. What is a possible numerical value for the forward force on the horse? Explain why,
4. What is a possible numerical value for the friction force on the cart? Explain why,
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5. Explain how Newton's first and third laws are represented in your previous answers.
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