Newton's Laws

An archer shot a 0.06kg arrow at a target. The arrow accelerated at 5,000 m/s/s to reach a speed of 50.0 m/s as it left the bow. During this acceleration, what was the net force on the arrow to the nearest Newton.?

• 833 N
• 300 N
• 3 N
• 83 N

A leaf fell from a tree branch. The path followed a zig zag pattern to the ground. Which of the following best describes why the leaf fell in a crooked path instead of a straight down path?

• Objects with irregular shapes never fall in straight lines.
• Air currents and gravity applied changing and unbalanced forces to the leaf.
• The upward force of the air on the leaf was greater than the downward force of gravity.
• Once the leaf was in motion, it continued moving in the same direction because the forces were balanced.

Four carts filled with sports equipment are pushed in the gym. Each student pushes with the same amount of force. Which cart has the greatest change in speed?

• 12 tennis rackets with a mass of 10 kg
• 18 exercise mats with a mass of 20 kg
• 15 sports balls with a mass of 15 kg
• 28 pieces of rope with a mass of 25 kg

A student raced toy cars on a track. The mass (.25 kg) and acceleration (8 m/s/s) of one car is recorded. What is the applied force?

• 1

• 2

• 3

• 4

A car was racing around a track. The acceleration are is 10 m/s/s. Using the data, assume the mass of the car does not change, what will the acceleration of the car be when 240 Newtons are applied to the car.

• 16

• 20

• 24

• 28

The diagram shows the cyclist applying a force of 150 N. There is air pushing on the biker at 84 N. The total mass of the cyclist and the bicycle is 100 kg. What is the acceleration of the cyclist?

• 0.66 m/s/s backwards, because the force of the air shows the cyclist.
• 0.66 m/s/s forward, becuase the applied force is greater that the force of the air.
• 2.3 m/s/s backwards, because the forces are opposite and not equal.
• 2.3 m/s/s forward, because the cyclist's inertia is greater than the force of the air.

A rocket carrying a space shuttle off the launchpad was active from 1981 until 2011. How can Newton's law of action-reaction best be applied to explain the movement of the rocket?

• As the fuel burns, gases push against the rocket, moving it upward.
• As the fuel burns, gases move out of the rocket and reduce the air resistance.
• As the fuel burns, the mass of the rocket decreases.
• As the fuel burns, the rocket moves faster.

Three boats with various mass are applying a force on the water. Which boat has the greatest acceleration?

• Boat 1 with a mass of 20 kg.

• Boat 2 with a mass of 1 kg.

• Boat 3 with a mass of 5 kg.

• You cannot tell from the information given.

Using the following list of examples. Which objects in the list experience unbalanced forces?

• book, ball, can sitting on a table

• ball, can, bird flying at constant speed

• can, swing, bird flittering back and forth

• book, ball, can, swing resting on the ground

A skateboarder is jumping off a skateboard to avoid hitting a wall. When the skateboarder jumps off, the board moves backwards. What explains why the skateboard moved in the direction described?

• An object in motion stays in motion.
• An object at rest stays at rest until an outside force acts upon it.
• friction slowed the skateboard down.
• action reaction forces.