Speed, velocity, and friction...oh my.
Newton's Laws
Calculating Average Speed
Vocab
Applying Newton's Laws
100
When Azaria tells her father that her bicycle is hard to pedal, he oils the chain. How does this make her bike easier to ride?
The oil reduces the friction force.
100
Whenever one object exerts a force on another object, the second object exerts an equal and opposite on the first.
Which of Newton's Laws is this?
Newton's 3rd Law
100
DAILY TRIPLE! Gabriel walks 5 km in 10 minutes. If Gabriel walks 2.5 km at the same speed, which is the best estimate of the time this will take? (speed = distance / time)
5 minutes
100
A runner measured the time it took him to run 5 km. What can he calculate from the distance and time measurements?
Speed
100
A child is jumping on a trampoline higher and higher, trying to touch the tree overhead. Identify the action and reaction of the child jumping on the trampoline.
Action: Child -> Trampoline
Reaction: Trampoline -> Child
200
One example is trying to increase friction: A) spreading sand onto an icy road B) reducing the weight of an object C) pouring oil into the engine of a car D) waxing the underside of a surfboard
Find the correct example and explain why it increases instead of decreases friction.
What is A - spreading sand onto an icy road.
Ice is near frictionless but the sand can break the ice surface and provide grip for vehicles or people traveling over it.
200
The acceleration of an object depends on the mass of the object and the amount of force applied.
Which of Newton's Laws is this?
Newton's 2nd Law
200
A police car drives at a constant speed of 100 miles per hour. How far can it travel in 10 hours?
D= Speed x Time
D= 100 m/h x 10 h
D= 1000 miles
200
Two students sit on a seesaw in a way that makes it horizontal (flat) and not move. When a third person pushes down on one side, that side moves down. When the seesaw isn't moving this is an example of BLANK but when the third person pushes, this is an example of BLANK.
1. ballanced forces
2. unbalanced forces
200
A car and truck are next to each other, slowing down to a stop applying the breaks at the same time.
1.Which object has more inertia,
2. why,
3. and what will happen to that object as a result?
1. The truck has more inertia
2. because it has more mass,
3. and it will take longer to stop.
300
A student observes their classmate propell a small and a large toy car up a ramp. The same amount of force was applied to each car. What would be the best hypothesis this student would expect to observe?
The large car will not travel as far as the small car.
OR
The small car will travel further than the large car.
300
An object at rest remains at rest, and an object in motion remains in motion at constant speed and in a straight line unless acted on by an unbalanced force.
Which of Newton's Laws is this?
Newton's 1st Law
300
If a train travels west at 80mph for 4 hours, what distance will the train travel? (speed = distance / time)
320 miles
300
Scientists discover a meteor moving 468km per minute traveling in a straight south to north direction..
1. What kind of rate description is this: speed, velocity or acceleration?
2. Convert to seconds.
3. Give the measurement including units and direction if applicable.
1. Velocity
2 and 3. 7.8m/s south to north
300
DAILY DOUBLE!! Two carts are pushed up identical inclined planes. One cart A has a mass of 5kg while cart B has a mass of 10kg. Each has 10N of force applied. What is the acceleration of each cart, and, which one will accelerate faster?
Cart A 2m/s2
Cart B 1m/s2
Cart A accelerates faster!
400
This graph shows the change in position of an object over time. How can you describe the movement of the object after 3 seconds?
It returned to the starting point, <Bonus: slowing at the end.>
400
What is the relationship between force and the mass of an object?
The greater the mass of an object, the greater the force needed to move it.
400
What two pieces of information are needed to determine how fast a truck is traveling?
distance and time
400
A force that slows objects down and opposes motion.
Friction
400
Which will happen to an object if the forces acting upon it are unbalanced?
The object will accelerate.
500
Describe the motion of each graph A to C.
**D is DOUBLE points for right, 100 points off for wrong!!!:
A. At Rest (not moving)
B. Constant Speed
C. Accelerating
D. Returning to start and slowing down.
500
A truck is traveling 70 mph with a heavy load in its trailer. After the truck is unloaded, it again travels 70 mph. The truck used only half the gas to go the same distance after it was unloaded. Which best explains why the truck used less gas after the truck was unloaded? (2nd law!!!)
The mass is less after the truck is unloaded. Thus it takes less force to accelerate and doesn't use as much fuel to get up to speed.
500
A car traveled 60 miles in one hour, while a bus traveled 120 miles in two hours. Which best describes the motion of the vehicles? (speed = distance / time)
The bus and car are traveling the same average speed of 60mph!
500
The rate of change and direction of an object.
Velocity
500
Which best describes the rate at which an object changes its POSITION over time?
speed