Physics , all the test and quizzes questions&answers
how many sig figs are in the number 0.0037010
5
the number of sig figs in 10001 is
5
a cannonball is fired at some angle into the air. in the first second it moves 5 meters horizontally. assuming it doesn't hit the ground and air resistance is negligible, how far does it move horizontally in the next second
5 m
a car with good tires on a dry road can decelerate (slow down) at a steady rate of about 5.0 m/s^2 when braking. if a car is initially traveling at 24.6 m/s how much time does it take the car to stop
5 s
wat is the quotient of 2.43 / 4.561 expressed to the correct number of sig figs
5.33 * 10 ^-1
if a car accelerates at a uniform 4.0 m/s^2, how long will it take to reach a speed of 22.2 m/s, starting from rest
5.6 s
suppose you take a trip that covers 190. km and takes 3.5 hours to make. your average speed is
54 km/h
a ball thrown upward takes 5.5 seconds to reach it peak. what velocity was it thrown with
54 m/s
a freely falling object starts from rest. after falling for 6 seconds, it will have a speed of about
58.8 m/s
how many sig figs are in the number 120.070
6
a 2kg ball is thrown at 3 m/s. what is the balls momentum
6 kg m/s
a car starts from rest and after 7 seconds it is moving at 42 m/s. what is the car's average acceleration
6 m/s^2
which of the following would exert the most pressure on the ground
a woman standing in high-heel shoes
speed is
a) a measure of how fast something is moving b) always measured in terms of a unit of distance divided by a unit of time c) the distance covered per unit time d) ALL THE ABOVE
one possible unit of speed is
a) miles per hour b) light years per century c) kilometers per hour d) ALL THE ABOVE
after a cannonball is fired into frictionless space, the amount of force needed to keep it going equals
zero, since no force is necessary to keep it moving
science
is an organized way of learning how nature works
an object moving in the +x direction experiences an acceleration of +2.0 m/s^2. this means the object
is increasing its velocity by 2.0 m/s every second
suppose a cart is being moved by a force. if suddenly a load is dumped into the cart so that the cart's mass doubles, what happens to the cart's acceleration
it halves
if the momentum of an object changes and its mass remains constant,
it is accelerating, there is a force acting on it, its velocity is changing
If the force acting on a cart triples, what happens to the cart's acceleration
it triples
a ball is thrown straight up, reaches a maximum height then falls to its initial height. which of the following statements about the direction of the velocity and acceleration of the ball as it is going up is correct
its velocity points upward and its acceleration points downward
a cannonball is thrown vertically into the air. at the very top of its trajectory the net force on it is
its weight
the unit of work is the
joule
whats the SI unit for mass
kilogram
compared to its weight on earth, a 10 kg object on the moon will weigh
less
you drive 6.0 km at 50 km/h and then another 6.0 km at 90 km/h. your average speed over the 12 km drive will be
less than 70 km/h
a scalar is a quantity that involves
magnitude only
the momentum of an object is defined as the objects
mass times its velocity
whats the SI unit for length
meter
potential energy formula unit
mgh joules
two objects, A and B, have the same size and shape, but A is twice as heavy as B. When they are dropped simultaneously from a tower, they reach the ground at the same time, but A has a higher
momentum
an airplane flying into a head wind loses ground speed, and an airplane flying with the wind gains ground speed. if an airplane flies at right angles to the wind, then ground speed is
more
if the force of gravity suddenly stopped acting on the planets, they would
move in straight lines tangent to their orbits
an object that has kinetic energy must be
moving
if the velocity verse time graph of an object is horizontal line, the object is
moving with zero acceleration
at the instant a ball is thrown horizontally with a large force, an identical ball is dropped from the same height. which ball hits the ground faster
neither. they both hit the ground at the same time
the first step of scientific method
observation
A rocket is abel to accelerate in the vacuum of space when it fires its engines. the force that propels the rocket is the force
of the exhaust gases on the rocket
kinetic energy of an object is equal to
one half the product of its mass times its speed squared
a scalar quantity has
only magnitude
friction is a force that always acts
opposite to an object's motion
whats the SI unit for time
seconds
chemistry
study of how matter is put together
biology
study of life
the ultimate source of energy for the most of the Earth is
sunlight
Science differs from other disciplines, such as history and the arts, because science relies on
testing explanations
an apple falls from a tree and 0.5 second later hits the ground. how fast is the apple falling when it its the ground (3 sf)
4.90 m/s
what is the average momentum of a 50 kg skateboarder who covers 400 m in 50 s
400 kg m/s
when a woman stands on a scale with two feet the scale reads 424 N. when she lifts one foot the scale reads
424 N
a person is attracted towards the center of Earth by a 440- N gravitational force. the force with which earth is attracted toward the person is
440 N
a car travels at 15 m/s for 10 s. it then speeds up with a constant acceleration of 2.0 m/s^2 for 15 s. at the end of this time, what is its velocity
45 m/s
a projectile launched horizontally hits the ground in 0.8 seconds. if it had been launched with a much higher speed in the same direction, it would have hit the ground (neglecting Earth's curative and air resistance) in
0.8 s
what is 0.674/ 0.74 expressed to the correct number of sig figs
0.91
In the sum A+B+C, A is accuurate to 1 decimal places, B is accurate to 2 decimal places, and C is accurate to 3 decimal places. what is the correct number of decimal places in the sum?
1
what is the difference between 103.5 and 102.24 expressed to the correct number of sig figs
1.3
the length and width of a rectangle are 1.125 m and 0.606 m, respectively. multiplying, your calculator gives the product as 0.68175. rounding properly to the correct number of sig figs, the area of the rectangle should be written as
0.682 m^2
add 1299 g and 45.1 kg and express your answer in milligrams (mg) to the correct number of sig figs
4.64 * 10^7 mg
what are the three types of PE
- gravitational potential energy -chemical energy -elastic energy
2.54 cm, how many meters
.0254
a pencil lies on your desk. if the Earth is moving around the sun at a speed of 30 km/s, how fast is the pencil moving relative to the desk? how fast is the pencil moving relative to the sun
0 km/s; 0 km/s
a ball is thrown straight up. at the top of its path its velocity is
0 m/s
a train travels 6 meters in the first second of travel, 6 meters again during the second second of travel, and 6 meters again during the third second. its acceleration is
0 m/s^2
when an object reaches terminal speed its acceleration is
0 m/s^2
a polar bear starts at the North pole. it travels 1.0 km south, then 1.0 km east, and then 1.0 km north to return to its starting point. this trip takes 45 min. what was the bear's average velocity
0.00 km/h
a volume of 100 mL is equivalent to which one of the following volumes
0.01 ML
a car is traveling north at 17.7 m/s. after 12 s its velocity 14.1 m/s in the same direction. find the magnitude and direction of the car's average acceleration
0.30 m/s^2, south
what is 0.2052/3, to the correct number of sig figs
0.348
you toss a ball at 5m/s straight upward. how much time will the ball take to reach the top of its path (3 sf)
0.510 s
a 5 kg blob of clay moving horizontally at 4 m/s has a head on collision with a 4 kg blob of clay that moves toward it at 2 m/s. what is the speed of the two blobs stuck together immediately after the collion
1.33 m/s
a weight lifter can bench press 171 kg. how many milligrams is this
1.71 * 10^8 mg
which one of the following numbers is equivalent to the number 0.0001776
1.776 * 10^-4
kinetic energy formula unit
1/2 mv^2 joules
A machine puts out 100 watts of power for every 1000 watts put into it. the efficiency of the machine is
10 %
the mass of a lamb that weighs 110 N is about
11 kg
the kings chamber of the great pyramid in egypt is 10.43 m long, 5.21 m wide, and 5.82 m high. what is the volume of the chamber in cubic feet, expressed to the correct number of sig figs (1m= 3.3 ft)
11,200 ft^3
a car starts from rest and accelerates uniformly at 4.0 m/s^2 for 5.0 s. then it slows down at a steady rate of 2.0 m/s^2 for 4.0 s. what is the final speed of the car
12 m/s
what is the GPE of a .60 kg blocks lifted to a height of 2.0 m
1200 J
which of the following numbers is the smallest
15 * 10^-3
to get her physics class, alice walks 0.25 mi to the bus stop. she takes the bus 1.2 mi to the train station. she takes the train 13 mi and walks the remaining 0.17 mi to her class. how far is her commute expressed to the correct number of sig figs
15 mi
a water rocket can reach a speed of 75 m/s in 0.050 seconds from launch. what is its acceleration
1500 m/s^2
a 20 N falling object encounters a 4 N of air resistance. the magnitude if the rest force on the object is
16 N
a crate falls from an airplane flying horizontally at an altitude of 1250 m, neglecting air drag, how long will the crate take to strike the ground (3 sf)
16.0 s
a person that has a mass of 75 kg weighs how much in pounds
165 lbs
what is the average speed of a cheetah that runs 88 m in 5 seconds
17.6 m/s
you are driving home on a weekend from school at 55 mi/h for 110 miles. it then starts to snow and you slow to 35 mi/h. you arrive home after driving 4 hours and 15 minutes. how far is your hometown from school
190 mi
how many sig figs are in the number 0.010
2
in the product A*B*C, A has 5 sig figs, B has 2 sig figs, and C has 3 sig figs. how many sig figs does the product have?
2
a girl pulls on a 10 kg wagon with a constant force of 20 N. What is the wagon's acceleration
2 m/s^2
a tow truck exerts a force of 2000 N on a car, accelerating it at 1 m/s. what is the mass of the car
2000 kg
suppose a small plane can fly at 170 km/h relative to the surrounding air. suppose also that there is a 60 km/h tailwind. how fast does the plans shadow move across the ground
230 km/h
a girl whose weight is 500 N hangs from the middle of a bar supported by two strands of rope. what is the tension in each strand
250 N
an object moves 15.0 m north and then 11.0 m south. find both the distance it traveled and the magnitude of its displacement
26.0 m, 4.0 m
what is the product of 12.56 and 2.12 expressed to the correct number of sig figs
26.6
an airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h north for 750 miles. what is the average speed for the trip
270 mi/h
express the sum of 420.77, 13.821, and 2317.8 to the correct number of sig figs
2752.4
a speed of 65 miles per hour is the same as which of the following ( 1.00 mi= 1609 m)
29 m/s
how much does a 3.0 kg bag of bolts weigh
29.4 N
in the quotient A/ B-C, A has 6 sig figs, B has 4 sig figs, and C has 3 sig figs. how many sig figs does the quotient have?
3
a 60 N object moves at 1 m/s. its kinetic energy is
3 J
you pull horizontally on a 75 kg box with a force of 500 N and the friction force on the crate is 250 N . the acceleration of the box is
3 m/s^2
an icicle falls off a roof and lands on the ground 0.80 s later. how high is the roof it fell from (3 sf)
3.14 m
the length and width of a rectangle are 1.125 m and 0.606 m, respectively. you calculate the rectangle's perimeter by adding these numbers and multiplying by two. your calculators display reads 3.462. to the correct number of sig figs, the perimeter should be written as
3.462 m
a runner ran the marathon (approximately 42.0 km) in 2 hours and 57 min. what was the average speed of the runner in m/s
3.95 m/s
a 15-N force and a 45-N act on an object in OPPOSITE directions. what is the net force on the object
30 N
a cannonball is launched from the ground at an angle go 30 degrees above the horizontal and a speed of 30 m/s. ideally (no air resistance) the ball will land on the ground with a speed
30 m/s
a 5 N force and a 30 N force acts in the same direction on an object. what is the net force on an object
35 N
if you run a complete loop around an outdoor track 400 m in 100 s, find your average velocity and average speed
4 m/s
Suppose that you exert a 300 N horizontally on a 50 kg crate on a factory floor, where friction between the crate and the floor is 100 N. What is the acceleration of the crate
4 m/s^2
a ball is moving at 6.0 m/s and has a momentum of 24.0 kg m/s. what is the balls mass
4.0 kg
an airplane increases its speed at the average rate of 15 m/s^2. how much time does it take to increase its speed from 100 m/s to 160 m/s
4.0 s
a car initially traveling at 60 km/h accelerates at a constant rate of 2.0 m/s^2. how much time is required for the car to reach a speed of 90 km/h
4.2 s
Given that 1.00 in= 2.54 cm and 1.00 yd= 36.0 in ., how many meters are in 7.00 yd
6.40 m
what is the sum of 2.67 + 1.976 + 2.1 expressed to the correct number of sig figs
6.7
a baseball is hurled into the air at an angle of 30 degrees above the horizontal and lands on a target that is at the same level as that where the baseball started. the baseball will also land on the target if it is thrown at an angle of
60 degrees
a cannonball is launched horizontally from a tower. if the cannon has a barrel velocity of 60 m/s, where will the cannonball be 1 second later (neglect air resistance)
60 m downrange
as a 600 N woman sits on the floor, the floor exerts a force on her of
600 N
A person weighs 650 N. What is the mass of the person
66.3 kg
what must be your average speed in order to travel 350 km in 5.15 h
68.0 km/h
what is the average acceleration of a car that goes from rest to 60 km/h in 8 seconds
7.5 km/h*s
a sportswear has a mass of 1500 kg and accelerates at 5 meters per second squared. what is the magnitude of the force acting on the sportscar
7500 N
how much force is needed to accelerate a 4.0 kg physics book to an acceleration of 2.0 m/s^2
8.0 N
if you are driving 72 km/h along a straight road and you look to the side for 4.0 s, how far do you travel during this inattentive period
80 m
a ball is thrown straight up. at the top of its path its acceleration is
9.8 m/s^2
a freely falling object starts from rest. after falling for 1 second, it will have a speed of
9.8 m/s^2
if a freely falling object were somehow equipped with a speedometer, its speed reading would increase each second by
9.8 m/s^2
a bag of sports equipment has a mass of 10.0 kg and a weight of
98 N
how much ( in newtons) does a 10.0 kg bag of grass seed weigh
98 N
the law of inertia states that an object
An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
what does newtons first law state
An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
what does newtons third law state
For every action, there is an equal and opposite reaction
what does newtons second law state
The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
based on your observations, you suggest that the presence of water could accelerate the growth of bread mold. this is
a hypthesis
suppose an object is in free fall. each second the object falls
a larger distance than in the second before
which of the following has the largest momentum -the science building at your school -a large truck parked in a parking lot -a tightrope walker crossing Niagra Falls -a pickup truck traveling down the highway
a pickup truck traveling down the highway
when you look at the speedometer in a moving car, you can see the car's
instantaneous speed
in the absence of air resistance, objects fall at constant
acceleration
the slope of a velocity versus time graph gives
acceleration
a ball thrown in the air will never go as far as physics ideally would predict because
air friction slows the ball
in the absence of air friction, the vertical component of a projectile's velocity doesn't change as the projectile moves
always false
T or F: whenever an object exerts a force on another object, the second object exerts a force of the same magnitude, but in the opposite direction to that of the first object
always true
in the absence of air friction, the horizontal component of a projectile's velocity doesn't change as the projectile moves
always true
at what part of a path does a projectile have minimum speed
at the top of its path
an auto manufacturer advertisies that their car can go "from zero to sixty in eight seconds." This is a description of what characteristic of the car's motion
average acceleration
A vector is a quantity that involves
both magnitude and direction
what is needed to describe a vector quanity
both magnitude and direction
the law of inertia applies to
both moving and nonmoving objects
the work of scientists usually begins with
careful observation
the metric system is preferred over the British system in science for the following main reason
conversions between metric quantities are especially easy because they are all related by factors of 10
you are on a frozen pond, and the ice starts to crack. if you lie down on the ice and begin to crawl, this will
decrease the pressure on the ice
a ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. during this time the acceleration of the ball is always
directed downward
distance and displacement are different from each other because
displacement involves direction
work formula unit
distance * force joules
an object at rest may have
energy
T or F: if a hockey puck were to slide on a perfectly frictionless surface, it will eventually slow down because of its inertia
false
T or F: mass is a vector quantity
false
T or F: the amount of matter in an object is its weight
false
if the acceleration of an object is zero, then the object cannot be moving
false
pressure is defined as
force per area
in physics work is defined as
force times distance
Accelerations are produced by
forces
if nellie newton pushes an object twice the force fir twice the distance, she does
four times the work
an object is dropped and falls freely to the ground with an acceleration of g. if it is thrown upward at an angle instead, its acceleration would be
g upward
an object following a straight-line path at constant speed has what acceleration
has 0 acceleration
speed def si unit formula
how fast m/s distance/time
velocity def si unit formula
how fast you go in a certain direction m/s^2 change in x/ time
acceleration def si unit formula
how your velocity changes m/s^2 change in velocity/ time
forces always occur
in pairs
one object has twice as much mass as another object. the first object also has twice as much
inertia
suppose that an object is moving with a constant velocity. which statement concerning its acceleration must be correct
the acceleration is equal to zero
suppose that an object travels from one point in space to another. make a comparison between the magnitude of the displacement and the distance traveled by this object
the displacement is either less than or equal to the distance traveled
a player catches a ball. consider the action force to be the impact of the ball against the players glove.
the force of the glove exerts on the ball
when multiplying several quantities
the quantities can have any combination of units
when adding several quanitites
the quantities must all have exactly the same units
a force of 7 N accelerates a mass of 7 kg at the rate of 1 m/s^2. the acceleration of a mass of 2 kg acted upon by a force of 2 N is
the same
a table tennis ball launcher is fired. compared to the impulse on the ball, the impulse on the launcher is
the same
an unfortunate bug splatters against the windshield of a moving car. compared to the force of the car on the bug, the force of the bug on the car is
the same
a ball is thrown upwards and caught when it comes back down. in the absence of air resistance, the speed of the ball when caught would be
the same as the speed it had when thrown upwards
physics
the study of energy, forces, and motion
The horizontal component of a projectile's velocity is independent of
the vertical component of its velocity
a collision is considered elastic if
there is no lasting deformation, the objects dont stick together, the objects that collide dont get warmer, after the collision, the objects have the same shape as before the collision
momentum of a system is conserved only when
there is no net external force acting on the system
a golf ball and a solid steel ball with the same diameter are dropped at the same time. which ball has the greater acceleration
they both have the same acceleration
galileo found that a ball rolling down one inclined plane would roll how far up another inclined plane
to nearly its original height
Consider a deer that runs from point A to point B. The distance the deer runs can be greater than the magnitude of its displacement, but the magnitude of the displacement can never be greater than the distance it runs
true
T or F: a force can be simply defined as a push or pull
true
T or F: inertia is the property that every material object has; inertia resists changes in an object†s state of motion
true
consider a car that travels between points A and B. The car's average speed can be greater than the magnitude of its average velocity, but the magnitude of its average velocity can never be greater can never be greater than its average speed
true
t or f: impulse is defined as the force exerted on an object times the time it lasts
true
t or f: momentum is defined as an objects mass times its velocity
true
if you lift loads up one story, how much work do you do compared to lifting just one load up one story
twice as much
compared to a sports car moving at 30 miles per hour, the same sports car moving at 60 miles per hour has
twice as much momentum
the slope of a position versus time graph gives
velocity
acceleration is defined as the CHANGE in
velocity divided by the time interval
the unit of power is the
watt
power formula unit
work / time interval watts
displacement def si unit formula
your change in position meters displacement= xf-xi
suppose you are in a car that is going around a curve. the speedometer reads a constant 30 miles per hour. which of the following is NOT true
your velocity is constant
