Forces

Changes in motion are caused by:

• unbalanced forces.

• balanced forces.

• mass.

• inertia.

Tags

NGSS.MS-PS2-2

An antique watch is pulled with a horizontal force F which makes an angle θ with the wall. T is the tension of the string and W is the weight. The relationship between T, F and W is...

• W = T + F

• F = T cos θ

• W = T cos θ

• F = W sin θ

Tags

NGSS.HS-PS2-1

According to Newton's Second Law of Motion, which object will have the greatest acceleration if all are thrown with the same amount of force?

• baseball

• tennis ball

• bowling ball

• table tennis ball

Tags

NGSS.MS-PS2-2

When is an object at equilibrium?

• When the object is at rest or at a constant velocity.

• When an object is at rest.

• When an object is accelerating upward.

• When an object is decelerating.

Tags

NGSS.HS-PS2-2

The biker travels at constant velocity. All of the following are true EXCEPT

• he has a net force acting on him.

• the normal force is equal to his weight.

• the force of friction acts opposite the direction of his motion.

• the force of friction is equal to the forward force he applies.

Tags

NGSS.HS-PS2-1

What is the net force?

• 3 N left
• 3 N right
• 7 N left
• 7 N right

Tags

NGSS.MS-PS2-2

An object resting on a surface does not fall because

• its weight and normal force are equal and opposite creating zero net force

• the surface doesn't allow gravity to pass through so the object is not pulled down

• friction between the object and the surface it is on stops the objects motion

• the surface exerts more force than the weight of the object so it cannot fall

Tags

NGSS.MS-PS2-2

What happens when unbalanced forces act on an object at rest?

• the object remains at rest
• the object begins moving in an unpredictable direction
• the object begins moving in the direction of the net force
• the object begins moving opposite to the direction of net force

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

A person steps out of the boat and onto the dock. As the person moves forward onto the dock, the boat moves backward. Which statement best describes the backward motion of the boat as the person steps forward?

• For every action there is an equal and opposite reaction.

• Every mass exerts a force on every other mass.

• An object at rest tends to stay at rest.

• Friction opposes the motion of an object.

Tags

NGSS.MS-PS2-1

Diagram below shows the way to pour out chilli sauce. The chilli sauce in the bottle can be easily poured out by moving the bottle down fast with a sudden stop.
The movement of the chilli sauce can be explained by...

• the concept of inertia.
• the concept of equilibrium of forces.
• the principle of conservation of momentum.
• the principle of conservation of energy.

Tags

NGSS.MS-PS2-2

NGSS.MS-PS3-5