Intro to Force and Motion Concepts

What is force?

• A push or pull that can cause motion
• The mass of an object
• An object's resistance to motion
• The speed of an object

Answer explanation

A force is defined as a push or pull that can change an object’s motion.

Tags

NGSS.MS-PS2-1

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Which of the following is true for balanced forces?

• They cause a change in motion
• They are equal in size and opposite in direction
• They increase friction
• They only occur on stationary objects

Answer explanation

Balanced forces cancel each other out, resulting in no motion.

What does a free body diagram show?

• The forces acting on an object
• The motion path of an object
• The speed of an object
• The mass of an object

Answer explanation

Free body diagrams represent all the forces acting on an object.

Tags

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If two forces act in opposite directions, how do you find the net force?

• Add them
• Subtract them
• Multiply them
• Divide them

Answer explanation

Subtract smaller force from larger to find the net force.

Tags

NGSS.MS-PS2-2

What is friction?

• A force that opposes motion
• A force that causes objects to accelerate
• A force that changes direction of motion
• A force that increases speed

Answer explanation

Friction opposes the relative motion between two surfaces in contact.

What factor does NOT affect friction?

• The roughness of the surfaces touching
• The color of the objects
• How hard objects are pressed together
• Adding lubricants to the surfaces

Answer explanation

Friction depends on surface type and force, not surface area.

Which scenario best demonstrates Newton's 1st Law of Motion (Inertia)?

• A car continuing to roll after the engine stops
• A balloon flying away when air escapes
• A ball accelerating when hit
• A rocket lifting off the ground

Answer explanation

Newton’s 1st Law describes an object in motion staying in motion unless acted on by an external force.

What is the equation for Newton's 2nd Law of Motion?

• f = m + a
• f = m / a
• f = m × a
• f = m - a

Answer explanation

Newton’s 2nd Law: Force = mass × acceleration.

Tags

NGSS.MS-PS2-2

Which of these is an example of action-reaction (Newton’s 3rd Law)?

• A ball bouncing off the floor
• A car coming to a stop
• A rock rolling downhill
• A box sliding on ice

Answer explanation

Newton’s 3rd Law: For every action, there is an equal and opposite reaction.

Tags

NGSS.MS-PS2-1

What does an unbalanced force do to an object?

• Keeps it stationary
• Changes its motion
• Makes it move faster
• Reduces friction

Answer explanation

Unbalanced forces cause changes in motion, such as speeding up or changing direction.

Tags

NGSS.MS-PS2-2