Forces Review

An object at rest will _______ if no outside forces are applied.

• Stay at rest
• Increase Velocity
• Decrease Mass

A greater applied force is required to move an object with a greater mass than one with a smaller mass.

• True
• False

The SI units for force are...

• Kilograms
• Newtons
• Meters per second
• Pounds

If a baseball and a cannonball are dropped from the same height at the same time, which ball will hit the ground first?

• the cannonball
• the baseball
• The balls land at the same time.
• the ball with the larger volume

A crumpled piece of paper hits the ground before a flat sheet of paper because

• the acceleration of gravity is greater on the  crumpled paper.
• there is more air resistance against the flat paper.
• the crumpled paper is more massive
• the crumpled paper is less massive.

According to Newton’s first law of motion, a moving object that is not acted on by an unbalanced force will

• remain in motion.
• eventually come to a stop.
• change its momentum.
• accelerate.

A hiker’s velocity begins at 1.8 m/s uphill and changes to 1.5 m/s uphill. How do you know that the hiker has a negative acceleration?

• His direction changed.
• His direction was unchanged.
• His speed increased.
• His speed decreased.

How does Newton’s third law explain how a rocket takes off?

• The rocket’s acceleration is positive, while the gasses acceleration is negative but the direction is the same. 
• The rocket is at rest until ignition.
• The hot gasses move in one direction, while the rocket moves in the opposite direction but with equal force.

Acceleration is caused by a force acting on a mass.

• Newton’s first law of motion
• Newton’s second law of motion
• Newton’s third law of motion

For a force on an object there is an equal and opposite force.

• Newton’s first law of motion
• Newton’s second law of motion
• Newton’s third law of motion