PHYS 112 SL- Oct. 6th

If the object in the image is in a state of static equilibrium, which of the following represents the missing force vector?

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• None of the above

A train is travelling to the right at a constant acceleration of 20 m/s². What is true about the net force on the train?

• F_netx= 0, F_nety= 0

• F_netx is to the right, F_nety=0

• F_netx =0, F_nety is downwards

• F_netx is to the right, F_nety is downwards

• There is no net force on the train

Which of the following situations describes an object in mechanical equilibrium?

• A rock sitting in the middle of the road.

• A rocket ship accelerating at a constant rate.

• A skydiver in free fall.

• A sailboat sailing at a constant velocity.

• A ball hanging at the end of a string.

A 20 kg wagon is pulled with a tension force of 40 N at a constant velocity. What is the magnitude of the kinetic force of friction? Answer to the nearest whole number and include units.

True or False?

Even though Object A is smaller, it will exert a force of the same magnitude back on Object B.

• True

• False

An 2 kg object experiences a force of 5 N, and accelerates at 2.5 m/s². What force must be applied to a 6 kg object so that it will experience the same acceleration?

• 10 N

• 15 N

• 2.4 N

• 1.67 N

• 5 N

A soccer ball is kicked by the foot of a soccer player during a game. If the soccer ball is the system, which of the following forces act upon it?

• The force of the soccer ball on the foot.

• The force of the Earth on the soccer ball.

• The force of the Earth on the soccer player.

• The force of the soccer ball on the Earth.

Which of Newton's Laws of motion states:

ΣF = ma?

• Newton's First Law of Motion

• Newton's Second Law of Motion

• Newton's Third Law of Motion

Which of the following images shows a box accelerating down a hill?

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A seal with a mass of 60kg slides along frictionless ice at a constant velocity of 1.75. It then reaches a rough patch of ice, which exerts a frictional force of 6 N. How long does it take the penguin to come to a rest?

Answer to one decimal place, and include units.