Motion is movement of an object. The object changes position relative to one location.
200
You travel to a city 200 km away in 2.5 hours. What is your average speed in km/hr?
80 km/hr
200
Calculate the momentum of a 14-kg bicycle travelling north at 2 m/s.
28 kg.m/s north
200
How are velocity and acceleration related?
acceleration = change in velocity/time
200
What unit is used to measure force?
the Newton
300
What is the difference between distance and displacement?
Distance is how far an object moves. Displacement is the distance between the starting and ending points and the direction of travel.
300
What is the difference between average speed and instantaneous speed?
average speed = total distance/time taken
instantaneous speed = speed of an object at one instant in time
300
A sports car and a moving van are travelling at a speed of 30 km/hr. Which vehicle will be easier to stop? Why?
The sports car will be easier to stop because it has a smaller mass, so it has a smaller momentum.
300
What is the direction of acceleration of an object when it speeds up? What is the direction of acceleration of an object when it slows down?
speeds up = same direction object is moving
slows down = opposite direction object is moving
300
Explain why it is important to include units when measuring quantities in science.
Units specify the quantity being measured. Without a unit, a number has no meaning.
400
John walks two kilometers north, three kilometers east and two kilometers south. What is his total distance? What is his total displacement?
distance = 7 km
displacement = 3 km east
400
Calculate the velocity of a mountain climber if that climber is moving northeast at a pace of 1.6 km in 1.4 hours.
1.1 km/hr northeast
400
Use the concept of inertia to explain why a greater force is required to move a tennis ball than a ping pong ball.
A ping pong ball has less mass, so it has a smaller inertia. Because it has a smaller inertia, it is easier to move.
400
A roller coaster car rapidly picks up speed as it rolls down a slope. As it starts down the slope, it speed is 4 m/s. But 3 seconds later, at the bottom of the slope, its speed is 22 m/s. What is its average acceleration?
6 m/s^2
400
Why is it important for time-keeping devices to move with a predictable, repetitive pattern?
A predictable, repetitive pattern ensures that the time interval remains constant.
500
What is your displacement if you walk 100 m north, 20 m east, 30 m south, 50 m west, and then 70 m south?
30 m west
500
A girl leaves school at 3:00 and starts walking home. Her house is 2 km from school. She gets home at 3:30. What was her average speed? Do you know her instantaneous speed at 3:15? Why or why not?
Her average speed was 4 km/hr or 0.067 km/min.
No, you do not know her instantaneous speed at 3:15 because data is not given for every moment she is walking home. Instantaneous speed is the speed at a specific moment in time.
500
Explain why a bowling ball slows down when it hits the pins using the law of conservation of momentum.
When the bowling ball hits the pins, some of its momentum is transferred to the pins. The ball slows down, and the pins speed up.
500
What is the acceleration of a car that travels in a straight line at a constant speed?
acceleration = 0
500
What are the SI units of velocity? What are the SI units of acceleration?