Science Contact Forces Quiz

Newtons third law of motion

For every action there is and equal and opposite reaction.

What is Kinetic Energy

KE is moving energy. More speed-more KE, Less speed-less KE

Define Force:

Force is the push or pull on an object. (can cause damage in/to an object)

Model a soccer player getting hit in the head by a ball. Explain how the contact force is equal.

The contact force is both equal and opposite because of Newton's third law, when the soccer player gets hit with the ball the force from the ball to player is the same from the force of the player to ball.

Difference between balanced and unbalanced forces. (Net force/acceleration)

Net force shows overall motion (unbalanced/balanced). Net force is a number- acceleration/motion to the side with more force.

Come up with your own force diagram word problem using tug or war and pull forces.

Kiera and Lucy are playing tug or war. Kiera pulls the rope 20n to the left, whereas Lucy pulls the rope 25n to the right. What is the net force?

Player 84 hits player 13 with a force of 5n. What is the force exerted on player 84? What is the force exerted on player 13?

The force exerted on each player is 5n because of Newton's third law.

Which system has the least KE? Why?

System C has the least KE only one out of the two things are moving so only one of the two objects that have KE. Whereas in system A and B both objects (Soccer ball & player + player & player) are moving so both have KE.

Which system had the lowest collision force? Why?

System C also has the lowest collision force because it has the lowest KE. Since system C just has one object moving (the player) it has less KE and collision force than both system A and B.

Which system(s) invole both objects having KE when they collide?

Both system A and B insole both objects have KE because both objects are in motion. But in system A if the ball was the only thing moving and not the player then it would not have both objects moving.

3 units for speed or rate:

miles/hr, m/min, inches/sec.

3 units for distance:

Miles, meters, inches.

How do you find distance?

Time x Rate or Speed

How do you find time?

Distance/Rate or Speed

How do you find Rate or Speed?

Distance/Time

Explain the difference between: stopping distance, reaction time, and braking distance.

Reaction time is the time it takes your brain to process there is trouble and then slam on the brakes. Braking distance is the distance it takes for your car to stop. Stopping distance is the total reaction time and braking distance.

Explain how AIRBAGS work in a car crash:

AIRBAGS spread out the force so there is less pressure in one area.

Explain how seatbelts work in a collision using the term INERTIA

Inertia keeps your body moving until the seatbelt stops your motion.

Energy of motion

Kinetic Energy

stored energy

Potential energy

energy moving from one object to another

KE Energy transfer

Energy changing from one type to the next.

Energy transformation

Energy cannot be created or destroyed- only transferred or transformed

Law of Conservation of Energy

Do things BEND when they collide?

yes

Do all things break in a collision?

no

KE transferring from object to object.

Motion

Measured in newtons, push or pull.

force

Force opposite motion as an object passes through the air

Air resistance

a force that acts between two objects that are in contact with one another

Friction

how fast an object moves

Law of Conservation of Energy