Semester 2 Study Guide
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?
0 J
What is the mechanical advantage of a single-fixed pulley?
1
An object weighing 75 N is dropped from the top of a building and falls a distance of 28 m to the ground. How much work does gravity do on the object from the time it is dropped tothe times it hits the ground?
2100 J
An 8 N force acts on a 5 kg object for 3 sec. What impulse is given the object?
24 kgm/s
A train moves at a constant speed of 50 km/h. How far will it move in 0.5 h?
25 km
Which of the following does not indicate velocity?
28 km from Los Angeles to Catalina Island
Which is an example of balanced forces acting on an object?
a leaf lying in the grass
A sound wave is an example of
a longitudinal wave
Which of the following situations best demonstrates the effects of friction
a parachutist descending to the ground
Light can be modeled as
a stream of particles called photons
Sound waves cannot travel in
a vacuum
Electromagnetic waves
can travel in space
The source of the energy when dynamite explodes is
chemical energy
Which material would make the best permanent magnet?
cobalt
A(N) // is defined as a machine made up of more than one simple machine
compound
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?
convert the mass to kilograms and convert the distance to meters
An object is released from rest and falls in the abscene of air resistance. Which of the folowing is true of its motion?
its acceleration is constant
Is the following kinetic or potential energy? A basketball passing through the hoop
kinetic
Is the following kinetic or potential energy? Moving skateboard
kinetic
Energy may change from one form to another but it cannot be created or destroyed
law of conservation of mass
A remote control uses which orm of energy?
light
The law that states that the unbalanced force acting on an object equals the object's mass times its acceleration is
Newton's second Law
The Antarctic South pole is the Earth's magnetic // pole
North
A // circuit has only one path for current to flow
Parallel
Is the following kinetic or potential energy? Rock at the edge of a cliff
Potential
Calculae the velocity of a cart moving with a momentum of 53 kgm/s and a mass of 18 kg.
2.9 m/s
Which type of lever is a crow bar?
first class
When the velocity of an object changes, it is acted upon by a(n)
force
The number of waves passing a given point per unit of time is called the
frequency
Where does energy go when it seems to have disappeared?
heat
Constructive interference creates
higher amplitude
The gravitational force on an object // as the object's mass increases.
increases
You are standing on a street corner, and you hear a fire truck approaching. As the fire truck gets closer to you, what hapens to the pitch?
it increases
How can the friction on a water slide be reduced?
run a constant stream of water down the slide
A (n) // is an inclined plane wrapped around a cylinder.
screw
Which type of lever is a wheel barrow?
second class
A mechanical wave moves through a medium, which can be
solid, liquid, gas
When 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?
terminal velocity
In total internal reflection, what angle must be exceeded by the incident ray?
the critical ray
Weight is best described as
the downward force exerted on objects due to gravity
what is the reaction force when you place cup on a table?
the force of the table on the cup
If two obejcts with different masses and traveling with different velocities collide, what law allows you to predict the motion of the objects after the collision?
the law of conservation of momentum
A force is continuously applied to an object, causing it to accelerate. After a period of time, however, the object stops accelerating. What conculsion can be drawn?
the object is experiencing some kind of friction
An object moves with a constant acceleratoin of 5 m/s^2. Which of these is true?
the object's velocity increases by 5 m/s each second
When white light passes through a prism, the light is separated into the colors in the visible spectrum because
the wavelengths of light travel at different speeds in the prism
The total amount of kinetic and potential energy in a system
thermal energy
A football, a hockey puck and a tennis ball all fall down in the abscence of air resistance. Which of the follwoing is true about their acceleration?
they all fall down with the same constant acceleration
Which statement about action-reaction forces is incorrect
they always act on the same object
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
they would not differ; they would be the same
Which type of lever is a hammer?
third class
Which type of lever is a mouse trap?
third class
A home is wired mostly in parallel. Why?
to maintain voltage
If a Mack truck and a lady bug have a head on collision, upon which will the impact force be greater?
truck
Which of the following is a vector (has both magnitude and direction)?
velocity
The source of all sound waves is a
vibrating object
In parallel, what factor is held constant throughout the circuit?
voltage
The amount of power a microwave oven uses is measured in
watts
Which of the following is a compound machine?
wheel and axle
In a collision is momentum conserved?
yes
Horsepower is the common unit of power in rating engines. However, the official SI unit of power is the
W
To find the amplitude, measure
either trough or crest to the rest position
A wave that consists of oscillating fields, radiating outward at the speed of light
electromagnetic waves
Electrical energy involves the movement of
electrons
A wave is a disturbance that transmits
energy
The ability to do work
energy
The frequencies of radio waves range from approximately 3.00 x 10^5 to 3.00 x 10^7 Hz. What is the range of wavelengths of these waves? Use 3.00 x 10^8 m/s as the speed of electromagnetic waves.
10 to 1000 m
A weightlifter presses a 400 N weight .5 m over his head in 2 seconds. What is the power of the weightlifter?
100 N
A series circuit has three resistors with resistance of 3,4, and 10 respectively. What is the total resistance of the circuit?
120 Ohms
The efficiency of a ramp is 75%. If the amount of work input is 240 J, what is the amount of useful work output?
180 J
A toy car moves 8 m in 4 s at a constant velocity. What is the car's speed?
2 m/s
Which of the following is a vector?
3 blocks east
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?
3 hours
A person starts from the ogigin, walks 8 km east the first day, and 5 km west the second day. What is the displacement of the person after 2 days?
3 km, east
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?
3 m
A wave has a period of 0.25 seconds. The frequency of the waves is
4 Hz
Our eyes can detect light only within a range of the electromagnetic spectrum called visible light. This range occurs at what wavelengths?
400 to 700 nm
What is the gracitational potential energy of a 54 kg box that is 8 m above the ground
4200 J
What is the average speed of a runner who runs at a constant pace for 500 m in 1.6 minutes?
5.3 m/s
A 10 kg dog chasing a rabbit north at 6 m/s has a momentum of
60 kgm/s north
If 0.5 A is flowing thorugh a househould light bulb and the bulb is plugged into a 120 V outlet, what is the bulb's power output?
60 watts
Cicadas produce a buzzing sound that has a wavelength in air of 2.69 m. If the speed of sound in air is 346 m/s, what is the period?
7.7 x 10^-3 s
Calculate the air resistance needed for a 75 kg object to reach terminal velocity.
735 N
A .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?
78.3 m/s
In the image shown, the time from beginning to the end of the wave train is 1 second. What is the freqeuency?
8.5
Starting from the origin, a person walks 6 km esat during the first day, and 3 km east during the next dy. What is the displacement of the person after two days?
9 km, east
Which of these creates magnetic fields?
Both magnets and moving charges
What is another unit used to label current?
C/s
Which of these is a derivation of Ohm's Law?
E = IR
Which part of the electromagnetic spectrum has the highest frequency?
Gamma rays
A disturbance at the boundary between two mediums
Surface wave
Alexandra was preparing to go on a hike in the woods. She gathered the equipment she would need and by chance, she placed her ocmpass near an electrical outlet. Although the compass was not moving, the compass needle turned because
The electric current in the outlet produced a magnetic field
Resistance in wires causes electrical energy to be converted into which form of energy?
Thermal energy
Which of the following is a conductor?
Tungsten
Changin speed or direction is best described as?
acceleration
Which of the following is not a factor in calculating momentum?
acceleration
After Peter removes his sweater by pulling it over his head, he notices that his hair is standing straight up. What causes this to occur?
accumulation of electrons
The loudness of a musical sound is a measure of the sound wave's
amplitude
The vibrations of a transverse wave move
at right angle to the direction of wave travel
If the net force on an object is zero then the object has
balanced forces
If the poles of two magnets repel each other,
both poles are south poles
When objects are moved further apart from each other, the force of gravity
decreases
A machine is a device that
decreases the amount of work done by a given force
On a velocity time graph, a line with a negative slope indicates what about the motion?
decreasing velocity
Displacement must always indicate?
direction
Power is calculated by dividing work by
distance
What is the equation for work? w= force x
distance
Which type of wave causes a medium to vibrate only in one direction parallel to the wave's motion?
longitudinal
Compressions and rarefactions are characteristics of
longitudinal waves
What is a group of atoms that all line up the same way and form small, magnetized regions within a material?
magnetic domain
The ratio of useful work output to input is a measure of
mechanical advantage
An object moves at a consant speed of 6 m/s. This means the object:
moves 6 meters every second
When an object slows down, going forward, its acceleratoin is?
negative
the combination of all the forces acting on an object is called the
net force
The law that states that every object maintains constant velocity unless acted on by an unbalanced force is ?
newton's first law
What are the units for work?
nm or J
The primary source of the sun's energy is
nuclear fusion
A (n) system exchanges energy with the outside
open
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 collision. What kind of event occurs?
perfectly inelastic collision
The time it takes for one wave, cycle, or oscillation is called
period
Light that travels in only one plane is called
polarized
Is the following kinetic or potential energy? A person at the top of a ladder
potential
Is the following kinetic or potential energy? An acorn hanging from an oak tree
potential
When energy is stored due to its position it is called // energy
potential
the stored energy resulting from the relative positions of objects in a system is called
potential
A quantity that measures the rate at which work is done is called
power
The rate at which work is done
power
Microwaves are higher in energy than
radio waves
If an object appears red under white light, which color is beinig reflected?
red
A pencil appears to bend when placed in water due to
refraction
The bending of light waves as they pass from one medium to another is
refraction