Forces and Motion

Imagine you are sliding a heavy box across the floor. What makes it difficult to keep pushing the box?

Tags

NGSS.MS-PS2-2

Friction:

1. Think about two different surfaces, like a smooth tile floor and a rough carpet. How would friction differ between these surfaces?

Why is it easier to throw a ball in outer space, where there is no air, than on Earth?

How can the shape of an object affect air resistance? Give an example.

A box is moving toward the right. Two forces act on the box: a force pushing the box to the right and a friction force. The two forces acting on the box are shown in the four force diagrams. Identify whether the speed of the box in each diagram will decrease, increase or remain constant.

c

Speed remains constant

Speed decreases

Speed increases

Tags

NGSS.MS-PS2-2

A box is moving toward the right. Two forces act on the box: a force pushing the box to the right and a friction force. The two forces acting on the box are shown in the four force diagrams. Identify whether the speed of the box in each diagram will decrease, increase or remain constant.

b

Speed decreases

Speed remains constant

Speed increases

Tags

NGSS.MS-PS2-2

A force that opposes the motion of an object is called (a)   .

• friction

• gravity

• heat

Answer explanation

A force that opposes the motion of an object is called friction. It acts in the opposite direction to the movement, slowing down or stopping the object. Gravity pulls objects down, while heat is not a force.

Tags

NGSS.3-PS2-1

A student wants to determine the amount of force needed to move a 100 gram block across 4 surfaces: a rug, glass, grass and concrete. Choose the best answer for Part A and Part B.

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

This is the free-body diagram of a box. Someone is trying to push the box, but it is too heavy. Which arrow represents gravity?

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

Match the following

• The force that attracts

  two objects with mass

  toward each other.

• Weight

• The amount of matter contained in an object or substance

• Air Resistance

• A measure of the gravitational force between objects

• Force

• An opposing force against objects moving through the air

• Gravity

• A push or pull required to

  move an object

• Mass

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-4

NGSS.MS-PS2-5