friction

F_N=100N, F_f=20N

• μ=5.0

• μ=0.2

• μ=1.2

• μ=0.1

What direction does friction act relative to motion?

• in the same direction
• in the opposite direction 
• need more information
• depends on the force

What is the coefficient of static friction if it takes 44 N of force to move a box that weighs 86 kg? 

• 0.78
• 0.51
• 0.05 N

• 0.58 N

Tags

NGSS.HS-PS2-1

A box takes 40 N to start moving when the coefficient of static friction is .54. What is the weight of the box? 

• 81 N
• 18 N
• 98 N
• 74 N

Tags

NGSS.HS-PS2-1

This photo represents...

• Air resistance

• water resistance

• friction force between 2 solid bodies

Tags

NGSS.HS-PS2-1

_____________ friction acts on objects that are not moving.

• sliding

• rolling

• static

• fluid

A hard wood floor has more friction than a carpet.

• true

• false

where is the centre of mass of this image

• at 20 mark
• at 42.5 mark
• at 50 mark
• at 100 mark

Tags

NGSS.MS-PS2-4

John (80 kg) is connected by a chord (5.7 m long) to a space station (5600 kg). Calculate how far the COM is away from John.

• 5.62 m

• 0.08 m

• 2.85 m

• 4 m

Tags

NGSS.MS-PS2-1

The coffee cup in the picture is at rest on the table. What is true about the Normal force?

• The normal force is exactly 15

• The normal force is less than 15

• The normal force is more than 15

• The normal force is -10

Tags

NGSS.HS-PS2-1