Worksheets8th Gr. Unit 3 1-2
Total questions: 17
Worksheet time: 14mins
After observing the magnetic cannon phenomena, Sanjan had the following questions. What questions do you think his classmates can investigate in the classroom? Select all that apply.
Does the incoming ball speed up as it nears the magnet?
Would this cannon work using balls of another material?
Since the magnets pull the balls toward them, what pushes the outgoing ball away?
How would this work with stronger magnets?
What energy conversions and transfers are associated with Newton’s Cradle? Select all that apply.
The KE from the last ball is converted to gravitational energy.
Gravitational energy is transferred from the balls to the surrounding air.
The kinetic energy is transferred from one ball to the next ball and the next ball until the last ball.
When a ball is lifted and released, gravitational energy is converted to kinetic energy.
When the ball hits another ball, kinetic energy is transformed into elastic energy and then transferred to the next ball, and the next. Elastic energy is transformed into kinetic energy and transferred to the last ball.
Consider the magnetic cannon as a system. What are all of the components (or parts) of the system?
The rulers and the ball bearings
The magnets and rulers
The rulers, the steel ball bearings, table, and the magnet
The magnet and steel ball bearings
Why is the box, sitting on the table, not moving?
No forces are acting on the box.
The table pushes up with the same force that gravity pulls down.
Gravity is keeping the box down on the table.
Gravity is pulling down, but the table is in the way.
The image is an example of a contact force. What statement below is true regarding contact forces?
If one force is a push, the other will also be a push; if one is a pull, the other will also be a pull.
Contact pairs always act in the same direction.
Contact pairs always act in opposite directions.
When two objects are touching, one force is always stronger than the other force.
The diagram represents a stuck vehicle.
What are all of the components of this system?
Vehicle 1, vehicle 2, and the rope.
Vehicle 1 and vehicle 2.
Vehicle 1, rope, vehicle 2, and the ground.
The rope and the ground only.
The diagram represents a stuck vehicle.
What do we know about contact forces as represented in the diagram?
Contact forces come in groups of 3 and act in opposite directions.
Contact forces can be from 1-3 objects. Sometimes they act in the same direction but other times they act in opposite directions.
Contact forces come in pairs and act in opposite directions.
A contact object touches one to three other objects and acts in a variety of directions.
The force between Earth and other objects is different from contact forces - whether or not you are in contact with the Earth, the reason for the force is not contact, rather it is gravity. Gravity is called a force that acts at a distance. What other forces act at a distance? Check all that apply.
Magnetic forces also act at a distance and come in pairs.
Friction is a force that acts at a distance but is stronger the closer the objects.
Magnets do not have to be in contact with each other to apply a force to the other.
The electrical force from a balloon attracting pieces of paper from a distance to the balloon.
We can now refer to the vehicle-pull-vehicle diagram as a model since it can be used to explain and predict the system’s behavior. Which model shows forces acting at a distance correctly?
Identify the forces acting [A, B, & C] within the floating magnets system.
A = Magnetic Force, B = Contact Force, C = Gravitational Force
A = Magnetic Force, B and C are contact forces
A, B, and C are all contact forces.
A and C = Gravitational Force, B = Contact Force
What is the relation between the force the lower magnet applies to the upper magnet and the force the upper magnet applies to the lower one? Check all that apply.
They are equal.
They get stronger as the magnets get closer to one another.
There are no forces.
They act in opposite directions.
A boulder is shown in the picture. Which is the correct reason that the boulder is not moving?
The boulder is too heavy for other forces to affect it.
No forces are acting on the boulder.
Gravity is holding the boulder down to the ground.
The ground pushes up with the same force as gravity pulls down.
A magnet is floating motionlessly above another magnet in a container. What are the forces acting on the lower magnet?
A is the Magnet’s weight; B is the Magnetic repulsion; C is the Contact Force between the test tube and the magnet.
A is the Magnet’s weight; B is the Contact Force between the test tube and the magnet; C s the Magnetic repulsion.
A is the Magnetic repulsion; B is the Magnet’s weight; C is the Contact Force between the test tube and the magnet.
A is the Magnetic repulsion; B is the Contact Force between the test tube and the magnet; C is the Magnet repulsion
What are the two forces acting on the upper magnet?
The magnet’s weight and the magnetic force attract it to the lower magnet.
The magnet’s weight and the magnetic force push it away from the lower magnet.
Two magnetic forces: one attracting it to the lower magnet and another pushing it away from the lower magnet.
The upper magnet’s weight and mass.
What is the relation between the two forces acting on the upper magnet to cause it to float?
The one acting upward is greater than the one acting downward.
The one acting downward is greater than the one acting upwards.
Both act in the same direction.
They are equal.
What is the relationship between the force the lower magnet applies to the upper magnet and the force the upper magnet applies to the lower one? Choose all that apply.
They are equal.
They act in opposite directions.
They get stronger as the magnets get closer to one another.
They act in the same direction.
On a visit to a science lab, Madison observes a blob of shiny material that is floating in the air. The blob is not moving. What can she conclude about the force(s) acting on the blob?
Gravity cannot be acting on the blob because it is not falling down.
Gravity must be acting on the blob or it would be floating.
There are no forces acting on the blob because it is not moving.
Each force acting on the blob has another one to cancel it out.
