Force and Friction

You push on a tree with 20 N of force. If the tree doesn't move, the tree is pushing back on you with _____of force.

• 20N 
• 40N 
• 10N 
• 70N

Tags

NGSS.MS-PS2-1

To calculate net force, when forces are acting in the same direction, the forces are ...

• added 
• subtracted 
• mutiplied 
• divided 

Tags

NGSS.MS-PS2-2

To calculate net force, when forces are acting in opposite directions, the forces are ...

• added 
• subtracted 
• multiplied 
• divided 

Tags

NGSS.MS-PS2-2

Friction is a force that acts in a(n) ___________ direction relative to a moving object.

• similar
• opposite
• parallel
• perpendicular

 What is the unit that measures force?

• Weight
• Net force
• Newton
• Kilogram

How would the absence of friction affect a marble traveling on a long, straight path?

• The marble’s speed would decrease.
• The marble’s speed would increase.
• The marble would stop immediately. 
• The marble would remain at a constant speed.

Tags

NGSS.MS-PS2-2

The main reason a baseball comes down when a boy tosses it up into the air is —

• magnetism is pulling the ball down

• the boy cannot see to catch it

• gravity is pulling down on the ball

• gravity pushes the ball in the air

Tags

NGSS.MS-PS2-4

How do you lower the friction force?

• By a smooth surface
• By a rough surface
• By not pushing hard
• By pushing down

Tags

NGSS.MS-PS2-2

Which of the following is an example of friction that is helpful?

• Brakes used on a bike
• Tires from a car on the road
• Tread on the bottom of your shoes
• All are examples that are helpful

The amount of friction depends on the weight of the objects pressing together.

• True
• False