Forces at Angles, Inclines and Friction

Which of the following is the best expression for the Normal Force?

• F_N = mg cos(ϴ)

• F_N = mg sin(ϴ)

• F_N = mg sin(180-ϴ)

• F_N = mg cos(90-ϴ)

Tags

NGSS.HS-PS2-1

Friction acts in a direction ___________ to the object's direction of motion.

• similar
• opposite
• parallel
• west

Normal force is [ ]to the surface that object contacts.

• parallel

• perpendicular

What are the units on the coefficient of friction?

• none
• Newtons
• meters
• kilograms

A box weighing 46 newtons rests on an incline that makes an angle of 25° with the horizontal. What is the magnitude of the component of the box’s weight perpendicular to the incline?

• 19N
• 21N
• 42N
• 26N

Tags

NGSS.HS-PS2-4

When the sum of all the forces acting on a block on an inclined plane is zero, the block

• must be at rest
• must be accelerating
• may be slowing down
• may be moving at a constant speed

Tags

NGSS.HS-PS2-1

An 8.0-newton block is accelerating down a frictionless ramp inclined at 15° to the horizontal. What is the magnitude of the net force causing the block’s acceleration?

• 0N
• 2.1N
• 7.7N
• 8.0N

Tags

NGSS.HS-PS2-1

A 1.0 × 10⁵-newton truck at rest on a hill that makes an angle of 8.0° with the horizontal. What is the component of the truck’s weight parallel to the hill?

• 1.4E3N
• 1E4N
• 1.4E4N
• 9.9E4N

Tags

NGSS.HS-PS2-4

A cart rolls down an inclined plane with constant speed as shown in the diagram below. Which arrow represents the direction of frictional force?

• A
• B
• C
• D

Tags

NGSS.HS-PS2-1

A 10.-newton block is sliding down a 30-degree incline at a constant speed. What is the force of friction?

• 5N
• 4.9N
• 10N
• 98N

Tags

NGSS.HS-PS2-1