8th Gr Unit 3 (5-7)

 Rosalie and Hakim investigated the relationship between the amount a spring is stretched and the size of the mass hanging from it. They recorded and graphed their data. How much do you think the spring will stretch if you hange 700 grams from it?  

• 7 cm because the spring will stretch 1 cm for every 100 grams of mass.

• 14 cm because the for every 100 grams of mass, the spring will double its stretch.

• We cannot predict how the spring will stretch based only on the mass of the object.

• 70 cm because the spring will stretch 10 cm for every 100 grams of mass.

Tags

MS-PS2-2

What is the mass of the spring that is stretched 6.5 cm? 

• 6500 grams

• 130 grams

• 650 grams

• 6.5 grams

Tags

MS-PS2-2

Does an object’s mass change if it is moved from Earth to outer space? What about its weight? Select 2 that apply.

• Both the mass and weight of an object will get smaller and smaller the farther away from Earth the object travels.

• Mass does not depend on location or the existence of gravity. It is a property of the object alone. Therefore, it will not change as the object is moved from Earth to outer space.

• Weight depends on gravity - the stronger the gravity, the greater an object’s weight. Therefore, an object’s weight will decrease and become almost zero as it is moved from Earth to outer space, where there is almost no gravity at all.

• Both the mass and weight of an object does not change based on where it is. Even if the object traveled to outer space, the mass and weight of the object would stay the same.

Tags

MS-PS2-4

Newton’s Third Law states that for every force, there is an equal and opposite force. Which statements provide an example of Newton’s Third Law.  Select 2 that apply. 

• Earth’s gravity pulls on the Moon, keeping it in orbit and at the same time, the Moon pulls back on Earth. 

• The harder you hit a ball with your racket, the faster it will move.

• As you sit on a chair, you push down on a chair and the chair pushes up on you.

• A bicycle keeps moving even after you stop peddling.

Tags

MS-PS2-1

Friction is a force and comes in pairs that act in opposite directions.   Your sister is trying to move her bed but is not having any luck as the bed won’t budge. Which free body diagram best represents the situation where the bed will not move? Which free body diagram represents when your sister’s push is enough to move the bed? Select 2 that apply. 

• The bed will move as the sister’s push is greater than the friction force.

• 
• Diagram B represents how the bed is not able to be moved by the sister.

• 

Tags

MS-PS2-2

When the ball is on its way down through point A, what force(s) are acting on it? 

• There are no forces acting on the ball.

• Only the force from Lisa’s push is acting on the ball.

• Only gravity and air friction are acting on the ball.

• Both gravity and the force from Lisa’s push are acting on the ball.

Tags

MS-PS2-2

When the ball is on its way back up through point B, what force(s) are acting on it?

• There are no forces acting on the ball.

• Only the force from Lisa’s push is acting on the ball.

• Only gravity and air friction are acting on the ball.

• Both gravity and the force from Lisa’s push are acting on the ball.

Tags

MS-PS2-2

Amelia hits a puck across the gym floor. She then observes the speed of the puck. Which of the following observations is most likely?

• The speed is constant because the force from Amelia’s hit is still acting on the puck.

• The speed is constant because there is no force acting on the side of the puck.

• The speed is decreasing because there is friction between the puck and the floor.

• The speed is zero because there is no force acting on the side of the puck.

Tags

MS-PS2-2

Maria pushes on a heavy rock but it does not move. Why does the rock not move?

• Nothing is moving, so there are no forces acting on the rock.

• Maria is exerting a force on the rock, but the force from the rock is stronger.

• There must be another force on the rock, opposing Maria’s push.

• The rock is heavier than Maria is.

Tags

MS-PS2-5

When you sit in your chair and push against a table, sometimes your chair moves and sometimes it does not. What are the forces acting on the system of you in the chair pushing on the table? Check 3 that apply.

• The combined weight of me and the chair pulled toward the floor by gravity and the contact force of the floor and the chair were balanced vertical forces.

• The contact force of the table and the chair

• The applied force of my hands as I push on the table is a horizontal force.

• The friction between the floor and the chair is a horizontal force.