Physics Fast Facts

A force of 8 Newton’s is applied to a crate so that it moves at a constant velocity of 1.5 m/s. What is the magnitude of the frictional force?

• 1.5 N

• 8 N

• 12N

• 0 N

Tags

NGSS.MS-PS2-2

What happens to the acceleration of an Atwood machine as the difference between the two masses increases?

• increases

• decreases

• does not change

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-4

Which of these is a correct sum statement for Fx?

• Fa - Ff = ma

• Fnet = Ff

• Fn/Fg

• Fa = ma

Tags

NGSS.HS-PS2-1

What's happening in this FBD?

• Forward acceleration

• Braking

• at rest

• constant velocity

Tags

NGSS.MS-PS2-2

Is it possible for the normal force to be zero?

• Yes. If the surface is horizontal.

• Yes. If the surface is vertical

• No. FN will always be less than Fg

• No. Fg will be less than FN.

Tags

NGSS.HS-PS2-1

Here are 3 FBD diagrams for an elevator. Consider them to be A, B, C. Which one shows an elevator moving upward but braking?

• A

• B

• C

• none of these

Tags

NGSS.MS-PS2-2

NGSS.MS-PS3-5

Here are 3 FBD diagrams for an elevator. Consider them to be A, B, C. Which one shows an elevator moving at a constant rate of 2.5 m/s?

• A

• B

• C

• none of these

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-4

The box on the incline is at rest due to friction. Which of these calculations would allow you to get the frictional force?

• mg cos theta

• mg sin theta

• normal force

• mg

Tags

NGSS.HS-PS2-1

Calculate the normal force for this situation if the angle is 30 degrees and the mass of the box is 1.5 kg.

• .75 N

• 7.5 N

• 13.0 N

• none of these is correct

Tags

NGSS.MS-PS2-2

Is it possible for the object in the diagram to be moving to the right and have this FBD?

• Yes. It's possible that the x forces were just left off the diagram.

• Yes. It could be moving at a constant velocity.

• No. The FBD shows that the system is in equilibrium.

• No. An FBD shows all F.

Tags

NGSS.HS-PS2-1