Download Semester 1 Exam Review Name: Measurement Measured in

Semester 1 Exam Review
Name:
Measurement
Mass
Length
Time
Velocity
Acceleration
Momentum
Impulse
Work & Energy
Force
Power
Measured in?
kg
m
s
m/s
m/s2
kgm/s
Ns or kgm/s
Joule or N∙m
Newton or (kg∙m)/s2
Watts or J/s
Vector or scalar
Scalar
Scalar
Scalar
Vector
Vector
Vector
Vector
Scalar
Vector
Scalar
The momentum before a collision is always (less/more/equal) when compared to the momentum
afterwards.
Do all objects in a vacuum fall at the same speed? YES. What would hit the ground first, a Whataburger
#2 (w/grilled onions & cheese) dropped by Diego from a height of 3.5m or a Whataburger #2 (w/grilled
onions & cheese) thrown horizontally by Stephanie from a height of 3.5m? SAME TIME
Projectiles follow what sort of path? Think shape. parabolic
Yuri throws a spicy chicken thigh at Sam’s head. The direction of the acceleration is ALWAYS DOWN!!!.
An object moving at constant speed is said to be in what? Equilibrium
Arnie dives headfirst into home plate on a suicide squeeze play. If Arnie is moving towards the right, in
what direction is friction? left
Erik attempts to tackle Frankie during football practice. Erik has the option to push or pull. Erik must use
(the) force.
If Frankie makes it away from Erik the force of gravity between the two decreases. If Frankie’s exit is
blocked off and Erik moves closer the force of gravity increases.
The amount of work done by a senior (who passed physics by turning in their HW on time) as they move
across a frictional stage is equal to their change in kinetic energy.
Jorge and Jorge and Jakob and Jacob join the US Olympic Bobsled team. The amount of potential energy
at the top of the bobsled run is (more/equal/less) than the kinetic energy at the bottom of the run.
After high school Manuel gets a job as a lion trainer. He recalls physics fondly and calculates the
potential energy of a lion on a platform 1.5m off the ground. The potential energy of the lion when it is
on a platform 3.0m off the ground would be exactly twice that of before.
Semester 1 Exam Review
Name:
Ashley pushes her 120N cat off the couch in a time span of 0.25s. What is the impulse imparted to the
cat?
Impulse equals a change in momentum. Impulse = force x time
Impulse = 120N x 0.25s = 30Ns
Santi tries to stop a free kick from Leo. The soccer ball has a mass of 0.8kg. The speed of the ball is 30.2
m/s by the time it reaches the goal. What is its momentum?
P=mv or momentum = mass x velocity
Momentum = 0.8kg x 30.2m/s = 24.16 kgm/s
Brandon the 70kg human cannonball is fired from a 300kg cannon at a velocity of 100 m/s. What is the
recoil velocity of the cannon?
For every action there is an equal and opposite reaction. Brandon shoots forward and the
cannon moves backward. The two momentums must be equal. Brandon’s momentum equals his mass
times velocity or 70kg x 100 m/s = 7000 kgm/s. Because the momentums are equal the momentum of
the cannon is 7000kgm/s. To find the velocity you setup the problem using the same formula. P=mv or
7000 kgm/s = 300kg x velocity. Velocity = 23.3m/s
During the course of a basketball game Nicolas travels up and down the court 76 times. Assuming that
the court is 55m long and Nicolas starts and stops in the same place, what is his displacement? His
distance traveled?
His displacement is zero because he starts and stops in the same place. His distance traveled is
equal to how far he went. Do not forget that he traveled the length of the court and back. In this case
this is equal to 76 trips x (2x55m) = 8360m.
If Javier can cover the length of a 20m tennis court in 1.3 seconds, what is his speed?
Speed is equal to distance divided by time. Speed = 20m/1.3s = 15.38 m/s
If Justin is taking a nap and has a dream in which he is chased by a physics textbook for 100m North,
followed by 30m West, and finally 20m South, what is his result displacement?
If you draw this out, you can form a triangle that is 80m north and 30m west of where he
started. The actual displacement is a straight line from where he started and where he stopped. You can
use the Pythagorean theorem to solve for displacement. 802 + 302 = c2 Do the math and c=85.44m
Semester 1 Exam Review
Name:
If Sergio sprints to class before the tardy bell at a velocity of 20m/s and slows down in front of a
principal to 2m/s in 0.5s, his acceleration is?
Acceleration is equal to the change in velocity over time. This value can be negative or positive.
His change in velocity is equal to velocity final minus velocity initial. In other words, a=(Vf-Vi)/t or a=(220)/0.5 = -36m/s2
Josh hits a golf ball with a velocity of 80m/s at an angle of 35 degrees. What is the horizontal velocity
component? Vertical?
Vx = V x cos (angle) or 80 x cos(35)= 65.53m/s
Vy = V x sin (angle) or 80 x sin (35) = 45.89m/s
Akaela goes wingsuit base-jumping and jumps off a 3000m cliff with a horizontal velocity of 20 m/s.
What is her vertical velocity after 1000m? Horizontal velocity? How much horizontal distance will she
cover during her flight?
Her horizontal velocity is a constant, so that will remain 20m/s. Her vertical velocity, or the
velocity in a ‘y’ direction is equal acceleration multiplied by time or a=vt. However we don’t know the
value of time so we must use the formula for distance or d=0.5at2. You can plug in 1000m for the
distance and then find time or *warning math ahead* solve for time and plug in to the first equation
which gives you v= sqrt(2ad). Either way, the vertical velocity after 1000m equals 140.07m/s. The
horizontal distance is equal to velocity multiplied by time or X=Vt. If you solved for time earlier you
found that time was equal to 14.28s. Throw that into X=Vt and you get 20m/s x 14.28s= 285.57m
Mr. McNutt opens a door but accidentally hits a freshman who did not read the sign on his door. The
5.0kg door smacks the freshman with an acceleration of 8m/s2. What is the force applied ?
The force applied is equal to mass times acceleration or F=ma. F=5*8=40N
Josie does 530J of work while bringing Mr. McNutt a breakfast taco. Assuming that the taco weighs 5N,
how far did Josie travel with the machacado taco?
Work is equal to force times distance or W=Fd. In this case 530J of work was done and the force
applied is the weight of the taco or 5N. Setting up our formula gives us 530=5 x d. d=106m
Amanda and Amanda are playing tug-of-war with Alex and Alex near a pit of alligators. If a 50kg alligator
jumps up and clamps down on the middle of the rope while Amanda2 is pulling left with 150 N of force
while Alex2 pulls right with 200N of force, what will be the acceleration of the alligator?
Force is a vector which means that the 200N of force going to the right will cancel out the 150N
of force going to the left. That leaves 50N of force going right. Force = mass x acceleration. 50N=50kg x
acceleration. Acceleration = 1m/s2
Semester 1 Exam Review
Name:
If Miranda has a mass of 50kg and is separated from her 1kg of Skittles by a distance of 3m, what is the
gravitational force between the two?
The formula for gravitational force is F= G x ((mass one x mass two)/distance2) where G is a
constant of 6.67*10^-11. Plugging in our information gives us F = 3.71x10^-11 newtons
If Mr. McNutt’s 1200 watt microwave takes 90 seconds to heat up his delicious non-cafeteria-food
lunch, what is the amount of work done?
Watts is a measure of power. Power is equal to work divided by time or P=W/t. Plugging in our
information gives us 1200=work/90. Solving for work gives us 108000.
Colton is being chased by a bull with a mass of 700kg. If the bull has 20000 joules of energy, at what
speed must Colton maintain to avoid the bovine?
Colton must move at least as fast as the bull in order to avoid it. Work is equal to a change in
kinetic energy. The formula for kinetic energy is KE=0.5mv2. We already have energy and mass. If you
solve for velocity you get 7.56m/s.
Mr. McNutt’s students don’t do their review and are forced to walk the plank. If the average student has
a mass of 70kg and the plank is 3.5x10^8 meters off the ground, what is their GPE?
If you got this far, I’m proud of you. Hopefully you do well. I know this is a lot to digest so I’m
going to post this on my teacher page on the south portion of the hcisd website. Anyways, the formula
for gravitation potential energy is GPE = mgh. In this case GPE=70x9.81x(3.5x10^8) or
GPE = 240345000000. You would not survive such a fall. This is the equivalent of skydiving from 217480
miles above the ground.