What keeps objects on a table in place when the tablecloth is pulled out from under them?

How many forces are acting on most moving objects?

• One

• More than one

Tags

NGSS.MS-PS2-2

1. A push or pull on an object is called a_____.

If an object is not moving, the forces on it are____. If an object has constant motion, the forces on it 

are_____.

If an object changes its speed, the forces on it are_____. 

If an object changes its direction, the forces on it are_____.

• field; not zero; unbalanced; balanced; unbalanced

• force; balanced; balanced; unbalanced, unbalanced

• reaction; not zero; unbalanced; not zero; balanced

• force; unbalanced; unbalanced; balanced; balanced

Tags

NGSS.MS-PS2-2

A ceiling fan is rotating in a circle at constant speed. Which phrase best describes the forces on the fan?

• The forces on the fan are unbalanced.

• The forces on the fan are balanced.

• The forces on the fan are constantly changing.

• There are no forces.

A worker pushes a wheelbarrow at a constant speed. The wheelbarrow has two opposite horizontal forces on it: the worker’s push, and friction. If neither force changes and the push force is larger than the friction force, how would you describe the motion of the wheelbarrow?

• constant speed

• slowing down

• at rest

• changing direction

Tags

NGSS.MS-PS2-2

1. Imagine you are wearing your seatbelt in a car that stops suddenly. Your body    is thrown forward but does not keep moving at the same speed the car was traveling. Your seatbelt is connected to the car. The seat belt provides ____  that causes you to _____.

• a balanced force; stop

• a balanced force; move forward

• an unbalanced force; stop

• an unbalanced force; move backward

Tags

NGSS.MS-PS2-2

If the forces on a shopping cart are balanced, what kind of motion might the cart have?

• Moving forward while slowing down

• Moving forward at constant speed.

• Moving backward while speeding up

• None of these

Tags

NGSS.MS-PS2-2

Which example demonstrate the effect of unbalanced forces on a train?

• All of these

• The train is stopped, and passengers are getting on and off.

• The train is moving at constant speed in a straight line along the track.

• The train is slowing down as it pulls into the station.

Tags

NGSS.MS-PS2-2

What causes an object rolling across the ground  to stop?

• Inertia

• Gravity

• Friction

• Magnetism

Tags

NGSS.MS-PS2-2

What is a push or pull?

• inertia

• force

• gravity

• friction

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2