Semester 2 Science Final Review Questions
a car accelerates from 25 km/hr to 55 km/hr in 30 seconds. what is its acceleration?
1 km/hr squared
a runner achieves a velocity of 11.1 m/s 9 seconds after he begins. what is his acceleration?
1.2 m/s squared
a car accelerates from 5 m/s to 25 m/s in 12 seconds. what is its acceleration?
1.67 m/s squared
a girl pedaling her bike at a velocity of 0.10 km/min. how far will she travel in 2 hours?
12 km
a 6.4 kg bowling ball would require what force to accelerate it down an alleyway at a rate of 3 m/s squared?
19.2 newtons
if the force of 110 N is applied by the student to a cart that is 55 kg, what is the acceleration of the cart?
2 m/s squared
the water in the buffalo River flows at an average speed of 5km/hr. if you and a friend decide to canoe down the river a distance of 16 kilometers, how may hours and minutes will it take?
3 hours and 12 minutes
if the average speed of a car is 45 km/hr, how far can it travel in 40 minutes?
30 km
Micheal jogged 200 m is 25 seconds and then 100 m in 15 seconds. he could find his average speed by dividing
300 m by 40 s
Jack walked 2 km in half an hour. What is his average speed during his walk?
4 km/h
what is the velocity if a car that traveled a total of 75 km north in1.5 hrs?
50 km/hr
a dvd player is added to a cart that is 55 kg. what is the new mass of the cart and equipment is a student is applying a force of 115.5 N and is accelerating the cart at 2.2 m/s squared?
52.5 kg
if a cars acceleration is 1.67 m/s squared, and it hits a guard rail with a force of 9000 newtons, what is the car's mass?
5389.2 kg
what is the velocity of a plane that traveled 3000 miles from New York to California in 5 hrs?
600 mi/hr west
what is the acceleration of a softball if it has a mass of .45 kg and hits the catcher's mitt with a force of 28 newtons?
62.2 m/s squared
a car accelerates from a standstill to 60 km/fr in 10 s. What is its acceleration?
6km/hr squared
a car is traveling at 100 km/hr. how many hrs will it take to cover a distance of 750 km?
7.5 hours
a car traveled 1025 km for El PAso to Dallas in 13.5 hours. What was its average velocity?
75.9 km/hr
a train is acceleration at a rate of 2 km/hr squared. if its initial velocity is 20 km/hr, what is its velocity after 30 seconds?
80 km/hr
an ant carries food at a speed of 1 cm/s. How long will it take the ant to carry a cookie crumb from the kitchen table to the ant hill, a distance of 50 m?
83.3 minutes
what is an example of horizontal movement?
a ball rolling on a flat table
what has a great amount of inertia?
a jumbo jet airplane taxiing down a runway
what is an example of vertical movement?
a person jumping straight up and down
what is an example of zero acceleration?
a person walking on a treadmill at a steady rate
what is an example of zero net force applied to an object?
a rope pulled equally from opposite ends
the formula for calculating acceleration is
a=(Vfinal-Vinitial)/ t
emily rides a bike around a circular track, and abby rides a straight track. Emily maintains a steady speed, but abby's speed increases. describe abby's acceleration
abby has positive acceleration in the direction of her motion because her speed increases but her direction does not change
If you subtract an object's initial velocity from its final velocity and divide by the time it took to change velocity, you are finding?
acceleration
a mover exerts a force on a piano the piano exerts force back together these forces are known as an
action/reaction force pair
when you whirl a ball on a string, in which direction is the centripetal force pointing?
along the string to the hand
Milo is running a race around a 400 meter track with straight sides and circular ends. Milo speeds up for the first half of the race and slows down for the second half of the race. Describe the acceleration Milo experiences as he speeds up
as he speeds up, velocity increases with acceleration in the same direction as the motion
Callie walked 18 m in 12s. She did not walk at a steady speed, so 1.5m/s was her
average speed
rosa wants to determine how long it will take her to drive from her house to her grandmothers house 5 km away. the time can be calculated using her car's
average speed
what is the force of two basketball players touching the basketball at the same time resulting in no motion?
balanced forces
joseph throws a baseball straight forward. at the same time, corey drops a baseball from the same height. what is true?
both baseballs fall at the same rate
Greg thinks the car he is in is stopped, and the car next to him is rolling backward. What else might be happening?
both cars are rolling forward, but Greg's car is rolling forward faster
which ball has the most momentum if they are all moving at the same velocity: a golf ball, a soccer ball, a tennis ball, or a bowling ball?
bowling ball
how does a rocket continue to accelerate after launch?
burning fuel loses mass, thereby speeding up
any force that is keeping an object moving in a circle is known as
centripetal force
On a roller coaster, the cars first climb a hill at a decreasing speed. Then the cars speed up as they go down the hill, before coasting at a steady speed on a straight track. Finally, the cars slow down as the ride ends. The cars have zero acceleration while
coasting on the straight track
what type of force is applied by the adult when lifting a child?
contact
Martin walks one mile west. Maya walks one mile east in the same amount of time. They have
different velocities
velocity is different from speed because velocity also includes
direction
A ball moves 5 meters in 10 seconds. what does this information tell you about the motion of the ball?
distance and time
lisa is watching a friend run a race, What does she need to know to find her friends speed?
distance and time
drew watches a car that appears to be moving forward. what is true?
drew is in another car moving backward
if one force is balanced by another the
effect is the same as no force at all
the motion of an object changes when you change
either its speed or its direction
a collision is a situation in which two objects in close contact transfer
energy and momentum
when one object exerts a force on another object, the second object exerts a force back on the first object that is
equal in size and opposite in direction
the strength of a reaction force is
equal to the strength of the action force
order a large rock, book, pencil, and feather from least inertia to most inertia
feather, pencil, book, large rock
when a soccer ball is kicked the action and reaction forces do not cancel each other out because the
forces act on two different objects
on what does relative motion depend when observing motion?
frame of reference
the momentum of a skateboard is not conserved because
friction acts on the wheel of the skateboard
if you increase the force on a box, it will have
greater acceleration
Pushing on an object will change what?
how it moves
the action of a golf club hitting a ball accelerates the ball in one direction. predict the direction in which the reaction force accelerates the club
in the opposite direction
one way to decrease acceleration is to
increase mass
a skater is moving at a constant speed. how can he increase his speed?
increase the force with which he pushes his feet against the ground
Newtons first law describes the tendency of objects to resist a change in motion this resistance is also called
inertia
melanie is acceleration as she skates on the ice. however, the speed at which she is skating has not changed. A possible explanation for this is that Melanie
is skating in a wide circle
two bumper cars collide. before the collision both have mass and velocity. according to the law of conservation how does the new total momentum compare to the original momentum?
it is equal
if you push or pull a moving object
its motion will change
you push two chairs in a straight line with the same force. One chair is more massive than the other. the more massive chair will have
less acceleration
in a canoe race, why might you want to use a less massive canoe that a more massive one?
less mass equals greater acceleration
what is the relationship of force, mass, and acceleration?
mass equals force divided by acceleration
the strength of the gravitational force between two objects depends on the objects
masses and the distance between them
what is true of momentum?
momentum is a measure of mass in motion
the mathematical relationship between momentum, mass, and velocity is
momentum= mass x velocity (p=mv)
a man is using a cart to move furniture onto a truck. why is the cart harder to accelerate when it is loaded with furniture that when it is empty?
more mass, more inertia, therefore, greater force is needed
a change of position over time is called
motion
AN objects distance-time graph shows that it moves 10 m during the first 10 s and moves 5m during the next 10s. the object has
negative acceleration
Imagine Carl throwing a ball straight up into the air. Describe the ball's acceleration and velocity from the time it leaves his hand until it reaches its highest point
negative acceleration at first, velocity decreases until it reaches its highest point
write the formula that relates momentum, mass, and velocity
p= mv, kg m/s
a person measuring motion needs to observe an object's
position at different times
adam started riding his bike to a friends house at a velocity of 4m/s west. as he neared the house, his velocity was 6m/s west. Adam's trip showed
positive acceleration
how does motion appear differently for you observing a moving bus and someone on a moving bus observing you?
relative motion is the same, but frame of reference is different
Mia walks 5 km north in one hour. Luisa walks 5 km south in the same time. How do their average speeds and their velocities compare?
same average speeds, different velocities
Chen rode his bike north with a speed of 20 m/s. Olivia rode her bike with the opposite velocity. She rode
south at 20m/s
hitting a ball can change its
speed and direction
if two objects in a collision receive equal and opposite forces for the same length of time the total momentum
stays the same
how do you find the total momentum of two objects moving at the same speed in opposite directions?
subtract the momentum of one object from the other object
you sit down in a chair to watch your favorite television show. the action force is your weight pushing down on the chair. what is the reaction force?
the chair pushing up on your body
a ball is rolling in a straight line. marcus kicks the ball at a 90-degree angle. what do you predict will happen?
the direction of motion of the ball will change
on what does average velocity depend?
the distance you are from where you stand
a bicyclist is riding in a straight line at a constant speed. what best describes the forces acting on the bike?
the forces are balanced
conservation of momentum occurs only when
the only forces acting on objects are action/reaction pairs
if the same force is applied to two objects with different masses, how will the objects accelerate?
the same force on different masses result in acceleration being different
if momentum is conserved, then the total momentum after a collision is equal to
the total momentum before the collision
a ted drags a chair across the floor, he feels the chair pull back on him. this is an example of which of newtons laws?
third
which of newtons laws is illustrated by a squid moving forward by shooting water out behind it? why?
third, action/reaction pairs
Suppose that you look out the window of a moving train at a stopped car. The car appears to you to move backwards. how would the motion of the train appear to someone in the car?
to someone in the car, it looks as if the train is moving forward
centripetal force keeps an object moving in a circle this force points
toward the center of the circle
action/reaction force pairs act on
two different objects
the motion of an object can be changed by an
unbalanced force
Roger observed an airplane flying overhead. He measured its speed and noted that it moved from north to south. Roger determined the plane's
velocity
describe the balls acceleration and velocity from the time it reaches it highest point until it reaches the ground
velocity of the ball changes direction and starts to increase with positive acceleration
you are standing in a crowded city bus. as the bus begins to move forward, you have a tendency to fall backward. what is the best explanation of this motion?
when the bus is still, both you and the bus are at rest. as the buss moves forward, you stay at rest, resulting in a tendency to fall backward
Micah and Will watched a skater skate at a steady speed around an oval rink. Micah said that the skater had no acceleration. Will said that the skater was accelerating. Who is right, why?
will is right. if the direction changes velocity changes. if velocity changes acceleration changes
