Speed and Velocity
Speed is the distance an object covers
divided by ________ .
Time
Acceleration is the change of _________ over time
Velocity
The Law of Inertia is the same as which of Newton's Laws?
Newton's First Law
A force acts on a box with a mass of 5 kg and it accelerates at 4 m/s2. What is the force?
20 N
A student walks 20 meters in 10 seconds. What is the student’s speed?
2 m/s
TRUE/FALSE
Speed and velocity are the same thing.
If FALSE, MUST correct to make it true.
FALSE
Velocity is speed AND direction.
TRUE/FALSE
When you slow down, your acceleration is negative.
If FALSE, MUST correct to make it true.
TRUE
Which of Newton's Laws is F=ma?
Newton's Second Law
What is Newton equivalent to?
kg*m/s2
A bike travels 60 meters east in 12 seconds. What is the bike’s velocity? (Speed is NOT enough)
5 m/s east
A car travels 300 meters east in 15 seconds. What is the car’s velocity? (JUST a speed will not be enough!)
20 m/s east
A go cart increases speed from 0 m/s to 25 m/s. It takes 5 seconds to accelerate. What is its acceleration?
5 m/s2
A book is resting on a table. It stays in place until someone pushes it. Which of Newton’s Laws explains why the book stays at rest?
Newton's 1st Law
(An object in motion tends to stay in motion. An object at rest tends to stay at rest. This is unless they are acted on by an unbalanced force.)
Calculate the force it takes to accelerate a 5 kg mass by 30 m/s2.
150 N = 150 kg*m/s2
A car increases its speed from 5 m/s to 15 m/s in 5 seconds. What is the car’s acceleration?
2 m/s2
A person walks at 1.5 m/s. It takes the person 20 seconds to complete the trip. How far did the person travel?
30 m
A car increases its speed from 10 m/s to 20 m/s in 5 seconds. What is the car’s acceleration?
2 m/s2
Two shopping carts are pushed with the same force. One cart is empty, and the other is full of groceries. Which cart accelerates more, and which law is at play?
The empty cart. Newton's 2nd Law (F=ma)
Calculate the mass of an object--it is pushed with 130 Newtons and accelerates 10 m/s2.
13 kg
A hockey puck slides across ice and eventually slows down and stops. Which force causes the puck to slow down?
Friction
How long does it take a bird flying at 10 m/s to fly 70 meters?
7 seconds
A skateboard slows down from 8 m/s to 2 m/s in 3 seconds. What is the skateboard’s acceleration?
–2 m/s² (negative because it is slowing down)
Two ice skaters start in the middle of the ice. They push off of each other and glide backwards to the walls. Which of Newton's Laws does this illustrate?
Newton's Third Law
Two carts are pushed with the same force of 12 N. Cart A has a mass of 3 kg and Cart B has a mass of 6 kg. Which cart has the greater acceleration? What is the acceleration?
Cart A; 4 m/s2
A box with a mass of 4 kg is pushed with a force of 20 N. What is the acceleration of the box?
5 m/s2