Newton's Laws
What is the Scientist's full name that created these laws. (Bonus: What scenario led him to make them?)
Sir Isaac Newton
Bonus: An apple fell from a tree and hit his head.
What is the unit for Force?
Newtons (N)
What is the formula for Velocity?
V = d / t
Velocity = distance / time
What is the formula for Work?
W = m x a x d
or
W = f x d
Work = force x distance
A 35kg girl is standing on a hill 85m above the ground. How much Potential Energy does she have?
Show your work and use the right units.
29, 184.75 J
PE = 35 x 9.81 x 85
Write out the Second Law of Motion completely.
Force = mass x acceleration
What is the formula for Force?
F = m x a
What are the units for Velocity and Acceleration?
m/s and m/s2
What is the unit for Work/Energy?
Joules (J)
A football player who weighs 72kg is running at a speed of 4.5m/s2 . How much Kinetic Energy is he carrying?
Show your work and use the right units.
KE = 729 J
KE = (0.5)(72)(4.5)2
KE = 36 (4.5)2
KE = 36 x 20.25
Write out the Third law completely.
For every action there is an equal and/but opposite reaction.
A ball weighs 32kg and, after being kicked, is accelerating at 64 m/s2. How much Force was applied to the ball from the kick?
Show your work and use the right units.
2,048 N
32 x 64 = 2,048
Write the formula for Acceleration.
a = vf - vi / t
acceleration = final velocity - initial velocity
divided by time.
What are the two categories of Energy we have learned about?
Potential
and
Kinetic
A 45kg dog is standing on her owner's 2m bed about to jump. How much Potential Energy does the dog currently have?
Show your work and use your units.
PE = 882.9J
PE = 45 x 9.81 x 2
Write out the entire First law.
An object in motion/at rest stays in motion/at rest, and an object at rest/in motion stays at rest/in motion, unless acted upon by an outside/another force.
A 25kg chair is pushed with 120N of Force. How fast will the chair accelerate?
Show all of your work
4.8m/s2
120 = 25 x a
120/25 = a
A woman starts her car and pulls out of her driveway at 20m/s. It takes her 10 seconds to get onto the road from her driveway. What is her current acceleration?
Show your work, and use the right units.
a = 2 m/s2
a = 20 - 0
a = 20 / 10
What is the formula for Potential Energy?
PE = m x g x h
Potential Energy = mass x gravity x height
A 120kg wrecking ball is swinging at 2.5m/s. How much Kinetic Energy does the wrecking ball carry?
Show your work and use the right units.
KE = 375 J
KE = (0.5)(120)(2.5)2
KE = 60 (2.5)2
KE = 60 x 6.25
A boy is climbing a steep hill, and has to dig his shoes into the gravel so he doesn't slip. Focusing on the boys feet and current state of motion, what law is being represented here.
Write the law and why.
The Third law of motion.
Because the boy's shoes are pushing the gravel back as he pushes himself forward. Creating an equal but opposite reaction to his forward movements.
A 4.5kg baseball is flying through the air after being thrown with 27N of Force. It's a windy day, so there is air resistance of about 10N. What is the ball's acceleration, and what is the Net Force?
Show your work and give me two answers.
Round to the nearest hundredth (0.01)
17N and 3.78m/s2
27 - 10 = 17N
17 = 4.5 x a
17/4.5 = a
A man is driving on the highway at 35m/s. He pulls onto the highway, and in 20 seconds accelerated to 65m/s. What was his acceleration in those 20 seconds?
Show your work and use the right units.
a = 1.5 m/s2
a = 65 - 35
a = 30 / 20
What is the formula for Kinetic Energy?
KE = 1/2 x m x v2
Kinetic Energy = 1/2 x mass x velocity2
A 2.5 kg ball is carrying 400 J of Potential Energy as it sits on a shelf. How high is the shelf?
Show your work and use your units.
Round to the nearest hundredth (0.01)
h = 16.31 m
400 J = 2.5kg x 9.81m/s2 x h
400 = 24.525 x h
400/24.525 = h