Physical Science Sem. 2 final
They all fall down with the same constant acceleration
A football, a hockey puck, and a tennis ball all fall down in the absence of air resistance. Which of the following is true about their acceleration?
the object is experiencing some kind of friction
A force is continuously applied to an object, causing it to accelerate. After a period of time, however, the object stops accelerating. What conclusion can be drawn?
2 m/s
A toy car moves 8 m in 4 s at a constant velocity. What is the car's speed?
25 km
A train moces at a constant speed of 50 km/h. How far will it move in .5 h?
law of conservation of momentum
If two objects with different masses and traveling with different velocities collide, what law allows you to predict the motion of the objects after the collision.
converts mass to kilograms and distance to meters
If you are given the mass of an object in pounds, the time in seconds, and the distance in feet, what must you do before you can calculate the momentum in SI units?
yes
In a collision is momentum conserved?
the force of the table on the cup
What is the reaction force when you place a cup on a table?
terminal velocity
When the gravitational forces and air resistance equalize on an object that is falling toward Earth and the object stops accelerating, what is the velocity of an object called?
28 km from Los Angeles to Catalina Island
Which of the following does not indicate velocity?
velocity
Which of the following is a vector (has both magnitude and direction)?
a parachute falling to the ground
Which of the following situations best demonstrates the effects of friction?
perfectly inelastic collision
a 700 kg car moving at 20 m/s collides with a stationary truck with mass 1400 kg. The two vehicles inter-lock as a result of the collusion. What kind of event occurs?
series
a _______________ circuit has only one path for current to flow
0 J
a boy pushes on a parked car with a force of 200 N. the car doesn't move. How much work does the boy do on the car?
surface wave
a disturbance at the boundary between two mediums
to maintain voltage
a home is wired mostly in parallel. Why?
can multiply and change the direction of an input force.
a machine is a device that
a solid, gas, or liquid
a mechanical wave moves through a medium, which can be
refraction
a pencil appears to bend in water due to
3 km east
a person starts from the origin, walks 8 km east the first day, and 5 km west the second day, what is the displacement of the person after two days?
power
a quantity that measures the rate at which work is done is called?
light
a remote control uses which form of energy?
120 Ohms
a series circuit has three resistors with resistance of 3,4 and 10 respectively. What is the total resistance of the circuit?
a longitudinal wave
a sound wave is an example of
3 m
a train of waves is moving at a speed of 30 m/s The frequency of the waves is 10 Hz. What is the wavelength?
4 Hz
a wave has a period of .25 seconds. The frequency of the wave is
energy
a wave is a disturbance that transmits
electromagnetic waves
a wave that consists of oscillating fields, radiating outward at the speed of light
100 W
a weightlifter presses a 400 N weight 0.5 meters over is head in 2 sec. What is the power of the weightlifter?
screw
a(n) --------is an inclined plane wrapped around a cylinder.
735 N
calculate the air resistance needed for a 75 kg object to reach terminal velocity
9.8 m/s
calculate the velocity of a cart moving with a momentum of 53 kgm/s and a mass of 18 kg.
acceleration
changing speed or direction is best described as?
931 s
cicadas produce a uzzing sound that has a wavelength in air o 2.69 m. If the seed of sound in airr is 346 m/s, what is it's period?
longitudinal waves
compressions and rarefactions are characteristics of
higher amplitude
constructive interference creates
a streram of particles called photons
light can be modeled as
polarized
light that tracels in only one plane is called
they would not differ; they would be the same
In the absence of air resistance, how would the acceleration of a 1.5 kg book and the acceleration of a 15 kg rock compare if the objects were dropped from the same height?
it increases
you are standing on a street corner and you hear a fire truck approaching, as it gets closer to you, what happens to the pitch?
3 h
A boat can move at a constant speed of 8 km/h in still water. How long will it take the boat to move 24 km?
W
horsepower is the common unit of power in rating engines. However, the official SI unit of power is the
inelastic collision
identify the collision in the image
neither
if a mack truck and a lady bug have a head on collision, upon which will the impact force be greater?
red
if an object appears red under white light, which color is being reflected?
voltage
in parallel, what factor is held constant throughout the circuit?
bulb A
in the image shown (combination circuit) which bulb burning out would mean that no current could flow through the circuit?
8.5
in the image shown, the time from beginning to the end of the wave train is 1 second. What is the frequency?
the critical angle
in total internal reflection, what angle must be exceeded by the incident
a vacuum
sound waves cannot travel in
north
te antarctic south pole is the earth's magnetic_______________ pole
wavelength
the Greek letter lambda is often used to represent a wave's ________?
energy
the ability to do work
watts
the amount of power a microwave oven uses is measured in
180 J
the efficiency of a ramp is 75%. If the amount of work input is 240 J, what is the amount of useful work output?
10 to 1000 m
the frequencies of radio waves range from approximately 3.00 x 105 Hz to 3.00 x 107 Hz. What is the range of wavelengths of these waves? Use 3.00 x 108 m/s as the speed of electromagnetic waves.
amplitude
the loudness of a musical sound is a measure of the sound wave's
refraction
the neding of light waves as they pass from one medium to another is called
power
the rate at which work is done
mechanical advantage
the ratio of useful work output to work input is a measure of
vibrating object
the source of all sound waves is a
chemical energy
the source of the energy when dynamite explodes is
potential
the stored energy resulting from the relative positions of objects in a system is
plug
the symbol in the picture represents a
period
the time it takes for one wave, cycle, or oscillation is called
thermal energy
the total amount of kinetic and potential energy in a system
at right angles to the direction of wave travel
the vibrations of a transverse wave move
frequency
tne number of waves passing a given point per unit of time is called?
either trough or crest to the rest position
to find the amplitude, measure
the downward force exerted on objects due to gravity
weight is best described as
nm or J
what are units of work?
magnetic domain
what is a group of atoms that all line up the same way and form small, magnetizzed regions within a material?
J/C
what is another unit used to label current?
distance
what is the equation for work? W= force X___________
4200 J
what is the gravitational potential energy of a 54 kg box that is 8 m above the ground?
0
what is the mechanical advantage of a single fixed pulley?
negative
when an object slows down, going forward, its acceleration is?
kinetic
when energy exists due to movement, it is called ___________ energy
potential
when energy is stored due to it's position, it is called ____ energy
decreases
when objects are moved further apart from each other, the force of gravity
force
when the volocity of an object changes, it is acted upon by a(n)
the wavelengths of light travel at different speeds than the prism.
when white light passes through a prism, the light is separated into the colors in the visible spectrum because
heat
where does energy go when it seems to have disappeared?
a leaf lying in the grass
which is an example of balanced forces acting on an object?
cobalt
which material would make the best permanent magnet?
pair of scissors
which of the following is a compound machine?
tungsten
which of the following is a conductor?
three blocks east
which of the following is a vector?
acceleration
which of the following is not a factor in calculating momentum?
both magnets and moving charges
which of these creates magnetic fields?
E=IR
which of these is a derivation of Ohm's law?
gamma rays
which part of the electromagnetic spectrum has the highest frequency?
They always act on the same object
which statement about action-reaction forces is incorrect?
first class
which type of lever is a crowbar?
third class
which type of lever is a hammer?
third class
which type of lever is a mouse trap?
second class
which type of lever is a wheel barrow?
longitudinal
which type of wave causes a medium to vibrate only in one direction parallel to the wave's motion?
direction
Displacement must always indicate?
electrons
electrical energy involves the movement of ??
can travel in space
electromagnetic waves
5.3 m/s
What is the average speed of a runner who runs at a constant pace for 500.0 meters in 1.6 minutes?
law of conservation of mass
energy may change from one form to another but it cannot be created or destroyed
kinetic
is moving a skateboard potential or kinetic energy?
time
power is calculated by dividing work by
78.3 m/s
A 0.015 kg pellet moving at 600 m/s hits a stationary .1 kg block and becomes embedded in the block. With what speed do they move off together?
60.0 kgm/s north
A 10 kg dog chasing a rabbit north at 6 m/s has a momentum of
24 kgm/s
An 8 N force acts on a 5 kg object for 3 sec. What impulse is given the object?
it's acceleration is constant
An object is released from rest and falls in the absence of air resistance. Which of the following is true of this motion?
moves 6 meters every second
An object moves at a constant speed of 6 m/s. This means the object:
run a constant stream of water
How can the friction on a water slide be reduced?
elastic collision
Identify the collision that explains the recoil of a shotgun
60 watts
If 0.5 A is flowing through a househole light bulb and the bulb is plugged into the 120 V outlet, what is the bulb's power output?
balanced forces
If the net force on an object is zero, then the object has
both poles are south poles
If the poles of two magnets repel eachother
potential
Is a rock at the edge of a cliff kinetic or potential energy?
9 km, east
Starting from the origin, a person walks 6 km east during the first day, and 3 km east during the next day, what is the displacement of the person after two days?
Net force
The combination of all the forces acting on an object is called the
increases
The gravitational force on an object ____ as the object's mass increases.
Newton's first law
The law that states that every object maintains constant velocity unless acted on by an unbalanced force is
Newton's second law
The law that states that the unbalanced force on an object equals the object's mass times it's acceleration is
nuclear fusion
The primary source of the sun's energy is
both A and C
according to the image (magnets attracting) , which pair of magnets could both be north poles?
accumulation of electrons
after Pete removes his sweater by pulling it over his head, he notices that his hair is standing straight up. hat causes this>
the electric current in the outlet produced a magnetic field
alex was preparting to go on a hike in the woods. She gathered the equipment she would need and by chance, she placed her compass near an electrical outlet. Although the compass was not moving, the compass needle turned because
open
an ---------- system exchanges energy with the outside
the object's velocity increases by 5 m/s each second
an object moves with a constant acceleration of 5 m/s2, Which one of these is true?
2100 J
an object weighing 75 N is dropped from the top of a building and falls 28 m to the ground. How much work does gravity do on the object from the time it is dropped to the time it hits the ground?
radio waves
microwaves are higher in energy than
decreasing velocity
on a velocity time graph, a line with a negative slope indicates what about the motion?
400 to 700 nm
our eyes can detect light only within a range of the electromagnetic spectrum called isible ligh. This range occurs at what wavelengths?
thermal energy
resistance in wires causes electrical energy to be converted into which type of energy?
