physics s1 final
newtons law of universal gravitation
Every object in the universe attracts every other object
What mathematical relationship between variables is suggested by a graph showing an L-shaped hyperbola that drops and flattens quickly?
Inverse-squared
power
the rate at which work is done
what do Kepler's laws of planetary motion say?
-the path around the sun is elliptical - the sun is located at 1 of 2 foci - a planet will always take up the same amount of space and time in orbit - the time it takes for a planet to orbit increases rapidly with the radius of its orbit
Patrick walks 70.0 m south in 150.0 seconds. He then walks 20.0 meters north in 30.0 seconds. What is his average velocity for the trip?
0.278 m/s south
An automobile of mass 1.46 E3 kg rounds a curve of radius 25.0 m with a velocity of 15.0 m/s. The centripetal force exerted on the automobile while rounding the curve is
1.31 E 4 N
A car increases from 10.0 km/s to 65.0 km/s in 5.0 seconds. Calculate the average acceleration of the car during these 5.0 seconds.
11 km/s2
A moving car has a kinetic energy of 7.08 E4 J. The mass of the car and its contents is 1,150 kg. What is the speed of the car?
11.1 m/s
David's new bike can accelerate from rest to 55.0 m/s in just 9.00 s. The combined mass of David and his bike is 235.43 kg. What is the magnitude of the unbalanced force that can cause the acceleration?
1440 N
A crane raises a 250-N weight to a height of 3.0 m in 5.0 s. The crane's power generated is
150 watts
A car traveling 35.0 m/s starts to accelerate at 3.00 m/s2. How far does this car travel after 4.00 seconds?
164 m
A train is slowing down with an average acceleration of −5.0 m/s2. If its initial velocity is 50.0 m/s, how far does it travel in 6.0 seconds?
210 m
A 47.0-kg diver jumped to a maximum height of 13.0 meters. From there, the diver falls from rest and hits the pool at a speed of 9.23 m/s. How much energy was transferred into thermal energy during the fall?
3990 J
A skier starts from rest and uniformly accelerates at 2 m/s2 down a slope. How far has the skier traveled at the end of 20 seconds?
400 m
Neglecting air resistance, how far does an object fall from rest after 3.0 seconds?
44 m
A net force of 125 N accelerates a 25.0 kg mass. What is the resulting acceleration?
5 m/s^2
Consider the common measurement: velocity = 55 mph west. What's considered the magnitude in this measurement?
55
The Empire State Building is 321 meters high. A dense rock is dropped from the top of the skyscraper. Neglecting air resistance, how long does it take for the rock to reach the ground?
8.09 s
A car with mass m traveling at speed v has kinetic energy K. What is the kinetic energy of a second car that has the same mass and triple the speed of the first car?
9 K
gravity
A force of attraction between objects that is due to their masses. -pulls objects towards center of earth
centripetal force
A force that causes an object to move in a circle
conservative force
A force that gets same work done in moving an object between two points independent of the path taken.
mass
A measure of the amount of matter in an object (kg)
weight
A measure of the force of gravity on an object (N)
Assuming all objects are moving with the same velocity, which statement describes the object with the smallest inertia? - A bowling ball rolls across a street and into a large soccer field. - A driver continues forward after his car takes a sharp turn. - A helicopter is following a high-speed pursuit across town. - A pebble is thrown in space and continues in a straight line.
A pebble is thrown in space and continues in a straight line.
work
Force exerted on an object that causes it to move
During an experiment, the pressure in an object was measured at various temperatures. A graph is made to show the relationship between the variables. Which of the following would be a standard title for this graph?
Pressure versus Temperature
What mathematical relationship between variables is suggested by a graph showing a half-parabola?
Quadratic (power)
types of kinetic energy
Radiant, thermal, motion, sound, electrical, mechanical
A mid-sized SUV is sitting at a traffic light when it is hit from behind by a compact car traveling at 30 m/s. The impact launches the SUV into the intersection. Which of the following is true during the collision?
The SUV applies a force on the car equal to the force the car applies on the SUV.
A player kicks a football into the air. It slows to a stop at its highest point in the air before falling to the ground. Which statement accurately describes the motion of the football?
The ball slows down in the air due to an unbalanced force.
A roller skater kept her balance and traveled in a perfect straight line. Her motion slowed down as she cruised along the street. Which of the following statements describes the forces on the skater? - The net force was not 0 on the skater during her motion. - The net force was 0, which is why the skater moved in a straight line. - The forces were unbalanced due to the skater's inertia. - The forces were balanced due to the action-reaction pair required to cruise.
The net force was not 0 on the skater during her motion.
Three motions are listed: a-an object changes direction b-an object changes position c-an object changes speed Which of the three is considered acceleration?
a and c
An object is standing still at the point of reference. Which of the following lines would represent this motion on a position-time graph?
a zero horizontal line
A horizontal force of 50 N is required to push a wagon across a sidewalk at a constant speed. a-What is the net (unbalanced) force acting on the wagon? b-What is the value of the force of friction acting on the wagon? c-If the mass on the wagon increased, use Newton's second law to explain what must change to get the object moving at constant speed.
a. The net force on the wagon is zero because its speed is constant. b. 50 N c. The force acting on the wagon must also increase. Newton's 2nd law says that as mass increases, an object's acceleration for a constant force will go down. In order to keep this object at a constant speed, you have to increase the force because force is directly related to acceleration.
Martha was leaning out of the window on the second floor of her house and speaking to Steve. Suddenly, her glasses slipped from her nose. The glasses hit the ground in 2.68 seconds. Neglecting the effects of air resistance, answer the following: What is the height of the window from the ground? What was the impact velocity of the glasses?
a. t=2.68 d=(1/2)gt^2 g=9.8 d=(1/2)(9.8)(2.68)^2 d=? d=4.9(7.18) d= 35.19 m b. vf=? vf^2=2gd g=9.8 vf^2=2(9.8)(35.19) d=35.19 vf^2=689.797 vf= 26.26 m/s
centripetal acceleration
acceleration toward the center of a curved or circular path
friction
any force that opposes motion or pending motion
what two factors affect how work is done
application of force, movement of something by that force
When you have an acceleration versus time graph, what does the area under the curve represent?
area under the curve is the change in velocity of the object
When air resistance is neglected, all falling objects near the Earth's surface will accelerate...
at the same rate
strong nuclear force
attractive force that holds the nucleus of an atom together
electromagnetic force
attracts negative electrons to the positive nucleus of an atom and underlies the interactions between atoms and molecules
open system (and ex)
both matter and energy can exchange freely between the system and surroundings (human body, open container)
The speedometer of a car reads 85 mph. It passes a truck in the next lane traveling at 75 mph. Which of the following statements is true?
both vehicles are scalar quantities
A 305 N unbalanced force was applied to an 25.0 kg object at rest. How far would this object travel after 8.00 seconds?
d=? f=ma d=1/2at^2 f=305 305=25a d=1/2(12.2)(8)^2 m=25 12.2=a d=6.1(64) t=8 d=390.4 The object would travel 390.4 meters.
A scientific law is expected to ________ a relationship that exists in nature.
describe
closed system (and ex)
energy can enter and leave, matter can not (earth, sealed glass container)
kinetic energy
energy of motion
t or f: The equal and opposite forces described by Newton's third law of motion will balance each other out in many cases.
false
true or false: time affects the amount of work done
false
if masses are equal the object traveling ______ has more kinetic energy
faster
non conservative force
force that does work that depends on path
Which of the fundamental forces is the attraction between two masses?
gravitational
types of potential energy
gravitational, elastic, chemical, nuclear
rank the fundamental forces in order from weakest to strongest
gravity - weak nuclear force - electromagnetic force - strong nuclear force
if masses are equal, the object at a _______ altitude has more potential energy
higher
elastic collision
if two objects collide and bounce off eachother
As a charge becomes stronger, other charges nearby will feel the electric force of attraction...
increase
According to Newton's second law, acceleration and mass have ________ relationship.
inverse
what describes the dependent variable?
it is called the respondent variable
If friction is present when an object is dropped and hits the ground, how does its kinetic energy just before striking the ground compare to its gravitational potential energy at the top of the drop?
kinetic energy is less
The mass of a steel wrecking ball is 1.75 E3 kg. What power is used to raise it to a height of 40.0 m if the work is done in 25.0 seconds?
m = 1.75 E3 kg w = Fd h = d = 40 m F = ma F = (1.75 E3)(9.8) t = 25 s P = w/t F = 17150 N p = ? w = (1.7 E4)(40) a = 9.8 m/s w = 6.8 E5 P = (6.8 E5)/25 P = 2.7 E4 watts
The moon has a mass of 7.35 E 22 kg and is located 3.84 E 8 meters from Earth. If a person on Earth has a mass of 47.0 kg, what is the gravitational force between this person and the moon? Remember to include your data, equation, and work when solving this problem.
m1 = 7.35 E22 kg Fg = (Gm1m2)/d^2 d = 3.84 E8 m (6.67E-11)(7.35 E22)(47)/(3.84 E8)^2 m2 = 47 kg 2.3 E14/1.47 E17 Fg = ? G = 6.67 E-11 Fg = 1.6 E-3 N
A ball of mass 0.32 kg and a velocity of +5.1 m/s collides head-on with a ball of mass 0.75 kg that is initially at rest. No external forces act on the balls. After the collision, the velocity of the ball which was originally at rest is +2.38 m/s. What is the velocity of the 0.32 kg ball after the collision? Remember to include your data, equation, and work when solving this problem.
m1v1o + m2v2o = m1v1f + m2v2f m1 = 0.32 kg m2 = 0.75 kg v1o = +5.1 m/s v2o = 0 m/s v1f = ? v2f = +2.38 m/s (0.32)(5.1) + (0.75)(0) = (0.32)(x) + (0.75)(2.38) 1.632 = 0.32x + 1.785 -0.153 = 0.32x x = -0.48 m/s
whats a measurement for inertia
mass
isolated system (and ex)
neither matter nor energy is permitted to exchange with surroundings (our universe)
A testable question in science leads to data that are
observable and measurable
what direction does a centripetal force act
perpendicular to the path of the moving object
weak nuclear force
responsible for different types of particle decay and radioactivity
free body diagram
shows all the forces acting on an object
The slope of a position-time graph is...
speed
potential energy
stored energy that results from the position or shape of an object
energy
the ability to do work
impulse
the product of the net force acting on an object and the length of time that it acts
what is youngs module (Y)
the ratio of stress to strain
Consider the scenario of a large truck hitting a small car at rest from behind. Which statement is true?
the truck and the car exert equal forces on eachother
The speedometer of a car moving to the north reads 50 mph. At an intersection, another car crosses in front of it, traveling at 50 mph. Which statement is the most accurate description of the motion of the vehicles?
the vehicles are moving at different velocities.
define the relationship between mass and weight
they are proportional at any given location great mass = great weight
In a free body diagram, the force of gravity will point...
toward the center of earth
t or f: force is directly proportional to acceleration when mass is constant
true
t or f: weight is directly related to mass
true
true or false: if an object is not moving, it has no momentum
true
what 2 things does friction depend on
types of surfaces in contact magnitude of pressing forces between surfaces
Cart A and Cart B are moving toward each other. They collide and come to rest at the point of impact. From this observation, we can conclude that the carts were...
were moving with equal and opposite momentum
Newton's first law of motion describes...
what an object at rest will do until acted on by an unbalanced force
inelastic collision
when two objects collide and stick together
