Learning Outcomes Sheet for test # 14
Unit 3, Lessons 1-2
Name : ________________________________
Vocabulary: Students need to learn and understand the meaning of the following vocabulary words
AND be able to apply them to a variety of situations. KNOW THESE DEFINTIONS BACKWARDS
AND FORWARDS!!!!
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position- the location of an object
motion –a change in an object’s position over time
frame of reference – an object or a group of objects from which a position or a motion is measured
speed –how fast an object’s position changes with time at any given moment
velocity –the speed and the direction of a moving object
acceleration – a change in velocity with respect to time
momentum –the mass of an object multiplied by its velocity
force – any push or pull by one object on another; measured in Newtons or pounds
gravity – the force that attracts all matter together
friction –a force that opposes the motion of one object moving past another
air resistance – a force that opposes the motion of objects moving through air
balanced forces – forces that act together on an object without changing its motion
unbalanced forces –forces that do not cancel each other out and that cause an object to change its
motion
Students will learn in class about the following topics. Be prepared to be assessed on them.
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2.
Motion has two parts: distance and direction.
Is this piece of paper moving? Yes, the paper appears to be at rest, but is moving relative to the Sun
since the Earth revolves around the Sun.
3. How could you be moving in one frame of reference, but not in another? An example answer: I could be at
rest in one frame of reference, but all the objects in that frame of reference could be moving in
relation to a second frame of reference. Ex. I could be sitting at rest in a car while the car is moving.
4. BE ABLE TO CALCULATE THE SPEED OF AN OBJECT GIVEN THE DISTANCE AND TIME. Ex.
An Olympic runner runs 100m in 10 sec. What is the runner’s speed? Speed = distance/time
Speed = 100m/10 sec = 10m/sec
5. What is the difference between speed and velocity? Give an example. Speed is hoe fast an object’s
position changes over time. Velocity combines speed with direction. For example, a car traveling at a
speed of 15mph might have a velocity of 15 mph west.
6. When the velocity of an object changes, it is accelerating.
7. Acceleration equals change in velocity over time for an object. Units of acceleration are units of velocity
divided by units of time: for ex. meters per second per second ((m/s)/s).
8. A car is accelerating from rest at a rate of 2 (m/s)/s. How fast will it be going after 4 s? 8 m/s. BE ABLE
TO SOLVE PROBLEMS LIKE THESE.
9. What is the direction of acceleration when traveling in a curve? The direction of acceleration moves
toward the center of the curve.
10. Which would be more difficult to stop, a truck or a skateboard? Why?
The truck; it has greater mass than the skateboard and thus greater momentum.
11. Who would be harder to stop: a professional hockey player skating at 4 m/s or a fifth grader skating at 4
m/s? Why? The hockey player would be more difficult to stop because he or she would have the same
velocity but more mass and momentum.
12. What changes the momentum of an object? Momentum changes when a change occurs in velocity or
mass. An object can gain or lose mass, or it can accelerate.
13. According to Newton’s law of universal gravitation, the force of gravity depends on distance and mass.
On Earth, which forces tend to slow an object down? Friction and drag
14. An object that is acted upon by unbalanced forces changes its motion.
15. A biker riding down the street is opposed by friction and air resistance.
16. What forces are exerted on an airplane as it is flying?
Thrust – when the plane engines push or pull the plane forward
Lift – as the plane moves forward, air moves around the wings and creates a force that raises
the plane into the air known as lift.
Drag – When broad, flat surfaces of the plane hit the air and pull back on the rest of the
plane. This pull, called drag, slows down the plane.
Weight –
17. What two forces tend to keep an airplane flying? Lift and thrust
18. How could you make an airplane rise faster into the air? You could increase its lifting force by changing
the wings to increase lift; design it to have less wind resistance; or decrease its mass to make it
lighter.
19. A force can cause an object to start moving, speed up, change direction, slow down, or stop.
20. What things influence the amount of friction between objects? How smooth the surfaces are, how hard they
are pressed together, and the weight of the objects
21. Some gravity exists between you and the person near you. Why are you pulled toward Earth and not toward
the other person? Gravity depends on mass, and Earth has a much greater mass than a person.
22. Newton’s law of universal gravitation states that every object in the universe is pulling on every other
object. Newton said that gravity depends on the masses of the objects and the distance between them.
Gravity decreases as mass decreases. Gravity decreases as distance decreases. This means that increasing
the mass increases the force, and increasing the distance decreases the force.
23. Without friction you would not be able to walk or move around because your feet would slip on
everything.
24. Friction usually increases with the roughness of a surface and friction increases with weight. Friction
decreases the speed of a moving object.
25. A pencil falls to the ground faster than a feather because broad, flat surfaces have more drag, and
therefore, more air resistance.
26. Balanced forces act on an object but do not change motion. A force that causes an object to change its
motion is called an unbalanced force.
27. Newton’s First Law of Motion: An object at rest tends to stay at rest, and an object in constant motion
tends to stay in motion, unless acted upon by an unbalanced force. This law is also known as the law of
inertia.
28. If there were no forces, such as friction or drag, an object in motion could travel forever in a straight line.
29. How does Newton’s First Law explain how seat belts prevent injuries in car accidents? During car
accidents, a car undergoes sudden decelerations. Your body, however, keeps traveling in a straight
line, possibly through the car windshield. Seat belts provide an outside force that changes your
motion and brings you to a stop.
30. Force = mass x acceleration As the force on an object increases, it’s acceleration increases. As mass
increases, acceleration decreases if the force stays the same.
31. How could you double the mass of a moving object and not change its acceleration? You would need to
double the force applied to the object so that its acceleration would not change.
32. Be able to solve problems involving Force = mass x acceleration. Ex. If the total force on a hot air
balloon is 600 Newtons and its mass is 300 kg, how fast will it accelerate?
600 N = 300 kg x acceleration, the acceleration would be 2 (m/s)/s.