The Man’sJeopardy

Learning Objectives1. Describe what a force is.2. Describe how balanced and unbalanced forces are

related to an object’s motion.3. Describe friction and identify the factors that determine the

frictional force between 2 objects.4. Identify the factors that affect the gravitational force

between two objects, and describe how they affect this force.

5. Explain why objects accelerate during free fall (by describing how gravity affects falling objects).

6. Apply Newton’s 1st Law of Motion to real world examples.7. Apply Newton’s 2nd Law of Motion to real world

examples.8. Apply Newton’s 3rd Law of Motion to real world examples.9. Explain how an object’s momentum is conserved &

calculate momentum.10. State the law of conservation of momentum.

RULES1. There will be round robin play and all

questions will be all-play except for the daily doubles.

2. The teams who answers correctly win the point value of the question.

3. If a team answers a daily double incorrectly, then that team will lose the number of points they bid, and any other team can “ring in” by raising their hand and answer at that point.

4. There are two daily doubles available.Let’splay

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Final Jeopardy

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Forces & Friction

Gravity Newton’s Laws 1&2

Newton’s 3rd Law & Momentum

Forces & Friction for 100

Which of the following is NOT an example of exerting a force: pushing a button, punching the PSU mascot, running to school? What effect do unbalanced forces have on an object’s motion?

Running to School (not exerting a force)

Unbalanced forces change an object’s motion.

Forces & Friction for 200

An object is falling toward the Earth at 9.3 m/s/s. Why is the object not falling at 9.8 m/s/s? What type of force resists the object’s motion in the opposite direction?

Air Resistance

Friction

Forces & Friction for 300

What force typically causes momentum to seem like it was NOT conserved? Example- the collision of two hockey players.

Friction

Forces & Friction for 400

Give an example of how decreasing friction is helpful.

Oiling a machine or bike, waxing a snowboard, using a cart with wheels to

move an object

Forces & Friction for 500Using the diagram below, what direction is the net force on the object? What is the net force? How could you balance the forces on the object?

Down, 50 N, Increase the upward force by 50 N

150 N

200 N

Gravity for 100

The force that acts on all objects on Earth and is the only force acting on an object in free-fall is ___________.

Gravity

Gravity for 200

How can the gravitational attraction between 2 objects be decreased?

Lower the mass and spread the objects further apart.

Gravity for 300

Suppose a planet with a mass of 100.5 x 1024 kg was discovered. Based upon the data above, what is a possible value for the gravitational pull of this new planet?

Any value from 1.1 to 2.3 would be correct. The best values would be between 1.1 and 1.5.

Planetary Body Mass (x 1024 kg) Gravitational Pull (relative to Earth)

Pluto 0.0013 0.1

Earth’s Moon 0.07 0.2

Mars 0.64 0.4

Earth 5.98 1.0

Jupiter 1900 2.4

The Sun 1,989,000 7.1

Gravity for 400Bob and Joe believe that heavier objects fall faster. They design an experiment to test out their prediction. What is their hypothesis? What is the independent or manipulated variable? What is the dependent variable? What are 2 variables that Bob and Joe should try to keep constant?

Hypothesis- Heavier objects fall faster.Ind. Variable- The weight or mass of the objects

Dep. Variable- Time it takes for the object to hit the ground OR acceleration

Constants- Height of the drop, air/wind resistance (if possible), same timer or timekeeper, etc.

Gravity DAILY DOUBLE!

Three satellites are orbiting the Earth. The distance from Earth is 6,000 km for Satellite A; 10,000 km for Satellite B; and 35,800 km for Satellite C. Which one would Earth have the greatest attraction for? Explain why.

Satellite A because it’s the closest.

Newton’s Laws 1 & 2 for 100

The ability of an object to resist a change in motion is called ___________.

Inertia

Newton’s Laws 1 & 2 for 200

What types of objects have the greatest inertia? What do objects in motion tend to do? What do objects at rest tend to do?

Heavier objects

Objects in motion tend to stay in motion

Objects at rest tend to stay at rest

Newton’s Laws 1 & 2 for 300An object accelerates at 4 meters per second2 for a force of 20 N. How much force is needed for an acceleration of 2 m/s/s for the same object? If the amount of force on a heavy object is the same as the amount of force on a lighter object, then which object will have the lower acceleration?

Half the acceleration for a constant mass = half the force, so 10 N

The heavier object will have the lower acceleration.

Newton’s Laws 1 & 2 for 400

A 100 kg person is skydiving. What is the force of gravity (or weight) acting on the skydiver?

F = m x a

F = 100 kg x 9.8 m/s/s

F = 980 N

Newton’s Laws 1 & 2DAILY DOUBLE!!!

Give two real world examples of Newton’s 1st Law (you may do this verbally instead of writing it down).

A car stops and your body moves forward, a car takes off and your body moves backward, etc.

Newton’s 3rd Law & Momentum for 100

According to Newton’s 3rd Law, for every action there is an _________ and ________ reaction.

For every action there is an equal and opposite reaction.

Newton’s 3rd Law & Momentum for 200

What are the action-reaction forces when a carpenter hammers a nail?

Action = hammer striking the nail

Reaction = nail pushes back on the hammer

Newton’s 3rd Law & Momentum for 300

How is momentum calculated?True or False. Change the underlined word to make it true. The momentum of an object is in the OPPOSITE direction of that object’s velocity.

Momentum = mass x velocityFalse, momentum is in the SAME direction as

the object’s velocity.

Newton’s 3rd Law & Momentum for 400

If the total momentum after a collision is 10 kg x m/s, then what was the total momentum before the collision? Explain how you know.

10 kg x m/s because momentum is conserved (remains the same and is not lost, only

transferred)

Newton’s 3rd Law & Momentum for 500

How can an object’s momentum increase? How does an object’s mass affect its momentum?

Moving faster or higher velocity

Greater the mass, the higher the momentum

Force Diagram

Draw a force diagram for a person pushing a large oven up a ramp toward the left. Label all of the forces acting on the box using arrows of the correct length.