PHY161 Exam 1 Review

A ball is thrown at an angle of 38° to the horizontal. What happens to the magnitude of the ball’s vertical acceleration during the total time interval that the ball is in the air?

• a. It decreases, then increases

• b. It decreases then remains the same

• c. It increases, then decreases

• d. It remains the same

A patient walks down the hallway near their hospital room to gain strength. As they walk, they push their IV pole on wheels (a pole that holds the medications in an intravenous bag which is connected to the patient by a tube/needle) in front of them. As they push the pole, the pole speeds up. Which statement is true?

• a. The force of the patient on the pole is larger than the force of the pole on the patient.

• b. The force of the pole on the patient is larger than the force of the patient on the pole.

• c. Both forces have the same magnitude.

A fireperson is sliding down a fire pole. As he speeds up, he tightens his grip on the pole, thus increasing the vertical frictional force that the pole exerts on the fireperson. When the force on his hands equals his weight, what happens to the fireperson?

• a. The fireperson descends with slower and slower speed.

• b. The fireperson descends with a smaller but non-zero acceleration.

• c. The fireperson continues to descend, but with constant speed.

• d. The fireperson comes to a stop.

• e. The acceleration of the fireperson is now upward.

A flying squirrel increases its area by spreading out and increasing air resistance. If a heavier squirrel and a lighter squirrel (both with the same surface area) jump out of the same nest at the same time, which would reach the level ground first?

• a. The lighter squirrel because they reach terminal velocity first

• b. The heavier squirrel because they reach terminal velocity first

• c. The lighter squirrel because they have more acceleration before terminal speed is reached

• d. The heavier squirrel because they have more acceleration before terminal speed

  is reached

• e. They both land at the same time.

A block of mass m slides down a rough incline with constant speed. If a similar block that has a mass of 4m were placed on the same incline, it would…

• Slide down at a constant speed

• Accelerate down the incline

• Slowly slide down the incline and then stop

• Not move

After launching, a projectile of mass 12 kg moves under the influence of gravity alone. What is the apparent weight when the mass is moving upward?

• 117.6 N

• 1. 0  N

• 58.8 N

• 235.3 N

• Need more information to answer

A train engine pulls two identical cars behind it. Car 1 is attached directly to the engine, and car 2 is attached to car 1. The engine and the cars are speeding up. The force on the engine on car 1 is _______ the force on car 2. 

• 1. Smaller

• 1. The same as

• Greater

• Not enough information is given

A tennis ball experiences air resistance. The tennis ball is hit so that it goes up and then comes back straight down. What is the direction of the air resistance?

• Always up

• Always down

• Up and then down

• Down and then up

You're pushing horizontally on a large crate, but it won't budge. According to Newton's third law, the crate pushes back on you with the same magnitude of force that you exert on it. Suddenly the crate breaks free and you can now push it along the floor

Now, the force exerted on you by the crate is ____  the force that you are exerting on the crate

• Greater than

• Equal to

• Less than

Find the resultant vector when the following are combined: 2 m west, 5 m east, and 7 m west

• 5 m east

• 7 m east

• 1. 4 m west

• 14 m east