Kinematics
True or False
Distance is a scalar quantity
true
This states that an object in motion remains in motion unless an unbalanced force acts upon it.
Newton's 1st Law
Momentum = Mass x _________
velocity
Work is _________ acting upon an object to cause displacement.
force
An object in motion has _________ energy.
kinetic
Displacement/time = ?
velocity
the natural tendency of an object to remain at rest or in motion unless acted on by an external force.
inertia
Momentum of a 1000-kg car moving northward at 20 m/s.
20 000 kg•m/s, north
A book falls off a table and onto the ground. Is this work?
(answer Yes or No)
yes
force is gravity
A bicycle has a kinetic energy of 100 Joules.
What kinetic energy would the bicycle have if it had the same mass and was moving with twice the speed?
400 J
Distance/time = ?
speed
Which Law best explains why you should wear a seatbelt?
Newton's 1st Law -
You wear a seat belt because when you brake your car or someone hits your car, a force is applied to the car....not to YOU! According to Newton's first law, you would keep moving in the direction you were previously moving.
A car possesses 20 000 units of momentum. What would be the car's new momentum if its mass was doubled (by adding more passengers),
40,000 units of momentum
The standard metric unit for work is the ______.
joule
J
Object has a mass of 2000 kg and is moving at 2m/s. What is the object's KE?
4000 J
In a relay race on a circular track, Eren ran the first 50 m in 5 seconds, Annie ran the second 50 m in 5 seconds, and Levi ran the last 50 m in 20 seconds.
What is the team's average speed? What is their average velocity?
include units
speed = 5 m/s
velocity = 0m/s
Newton's 3rd Law
as the rocket expels hot gas downwards, the reaction force pushes the rocket upwards.
A 50 kg quarterback is running at 5 m/s down the field.
A 90 kg halfback is running at 3 m/s down the field.
Which has more momentum?
90 kg halfback
90 x 3 = 270 units of momentum
50 x 5 = 250 units of momentum
Drake and Josh ran up a hill. Drake is twice as massive as Josh; yet Josh ascends the same distance in half the time. Who has the most power?
they have the same amount of power
Josh does one-half the work yet does it one-half the time. The reduction in work done is compensated for by the reduction in time.
A bicycle has a kinetic energy of 100 Joules.
What kinetic energy would the bicycle have if it had twice the mass and was moving at the same speed?
200 J
What is the displacement of the cross-country team if they begin at the school, run 10 miles and finish back at the school?
0 miles
These are the standard units used for describing the values of Force
Newton
N
kg m/s^2
A large truck collides with a small bicycle.
Which vehicle experiences the greatest force of impact?
both have the same
conservation of momentum
Vi and Jayce are lifting weights. Vi lifts 10 kg dumbbells 10 times in a minute. Jayce lifts the same dumbbells 10 times in 10 seconds. Who has more power?
Jayce
Same amount of work but less time.
A 5 kg object is lifted to a height of 10 m. What is the potential energy of the object?
490 J
m x g x h
g = 9.8 m/s^2