Physics practice test questions

Jack stands in front of a plane mirror. If he is 2.5 feet away from the mirror, how far away from jack is his image? A. 2.5 feet B. 3 feet C. 4.5 feet D. 5 feet

D (2.5 + 2.5=5 feet, distance from an object to the mirror is identical to the distance from the mirror to the image = double)

Coulomb's law has to do with? A. electrostatic interaction B. rigid body motion C. heat conduction D. universal gravitation

A (like charges repel and opposite charges attract with a force proportional to the product of the charges. attraction vs repelling)

A hummingbird's wings beat at 25 beats per second. What is the period of the wing beating in seconds? A. 0.04 s B. 0.25 s C. 0.4 s D. 4 s

A (so if it is beat at 25 per second, the period of each wing beat is 1/25 which is 0.04 s)

Which of these objects has the greatest momentum? A. a 1,250-kg car moving at 5m/s B. an 80-kg person running at 4m/s C. a 10-kg piece of meteorite moving at 600 m/s D. a 0.5-kg rock moving at 40 m/s

A (the car is moving with the most momentum at 1,250-kg.)

An object moves 100 m in 10s. What is the velocity of the object over this time? A. 10 m/s B. 90 m/s C. 110 m/s D. 1,000 m/s

A (velocity is the change in distance over time. So 100m /10s is the same as 10)

A balloon with a charge of 5UC is placed one from another balloon with the same charge. What is the magnitude of the resulting repulsive force? A. 0.18 N B. 1.8 N C. 10^-3 N D. 5 x 10^-3 N

B

How far will a car moving with a constant velocity of 40 mi/hr travel in 15 minutes? A. 2.7 B. 10 C. 40 D. 600

B

Ocean waves build during a storm until there is a vertical distance from high point to low of 6 meters and a horizontal distance of 9 meters between adjacent crests. The waves hit the shore every 5 seconds. What is the speed of the waves? A. 1.2 m/s B. 1.8 m/s C. 2.0 m/s D. 2.4 m/s

B

Which one has the lowest density? A. water B. cork C. Aluminum D. Steel

B ( Cork has holes throughout that reduce the volume of matter present, cork is replaced by air, making it less dense than many other materials)

The specific heat capacity of tin is 0.217 J/(gC) which of these materials would require about twice as much heat as a tin to increase the temperature of a sample by 1C? A. copper (0.3844 J/gC) B. Iron (0.449 J/gC) C. gold (0.1291 J/gC) D. aluminum (0.904 J/gC)

B (basically if you add .217 to itself = .434 which would rule out A, C, D)

Why doesn't a raindrop accelerate as it approached the ground? A. Gravity pulls down at a constant rate B. Air resistance counteracts the gravitational force C. Its mass decreases, decreasing its speed D. Objects in motion decelerate over distance.

B (gravity causes acceleration. Losing mass does not change the acceleration.)

Which one has the highest density? A. mist B. water C. steam D. Ice

B (ice floats on water)

What is the momentum of an object of 1.5 kg mass moving with a velocity of magnitude 10 m/s? A. 1.5 (kg-m)/s B. 15 C. 150 D. 1500

B (multiply 1.5 by 10 =15.0)

Which of these can you conclude from Ohm's law? A. Voltage and current are inversely proportional when resistance is constant B. ratio of the potential difference between the ends of a conductor to current is a constant, R. C. Voltage is the amount of charge that passes through a point per second D. Power (P) can be calculated by multiplying current (I) by voltage (V)

B (the law says Current & resistance are inversely related, both are proportional to voltage. the formula used is I=V/R so the resistance is constant, independent of the current which is R)

When calculating an object's acceleration, you must do which of the following? A. Divide the change in time by the velocity B. Multiply the velocity by the time C. Find the difference between the time and velocity D. divide the change in velocity by the change in time

D (Acceleration is defined as the change in velocity over time)

What is the purpose of a switch in a circuit? A. to reverse the direction of alternating current B. to increase the voltage of the batter or cell C. to increase the resistance of wires in the circuit D. To allow the circuit to open & close

D (a switch interrupts the electrical circuit or allows the current to flow from one conductor to another)

Two objects attract each other with a gravitational force of 12 units. If the distance between them is halved, what is the new forced of attraction between the two objects? A. 3 B. 6 C. 24 D. 48

D (decrease by two means to increase by 2 as well so 2x2=4 which then multiply that by 12 =48)

Sublimation is the change in matter from solid to gas or gas to solid without passing through a liquid phase. Outside of the laboratory, which solid provides the best example of this? A. Iron B. silver C. salt crystal D. dry ice

D (dry ice is the only thing that transforms into a gas without turning into a liquid first)

What is Coulomb's law?

predict the strength of the attractive/repulsive force between two particles (attraction vs repelling)

What is force? (F)

push that starts or stops an object's motion

What is a scalars?

quantity only having magnitude (size)

Heat capacity is?

resistance to temperature change

What is mechanical energy?

sum of objects kinetic & potential energies

What is convection?

Heat is transferred away from an object by the movement of gases or fluids

What is specific density?

density when compared to water

What is velocity ?

distance covered by an object over a giver period of time

What is a wavelength?

distance from the PEAK of one wave to the next

What is amplitude?

distance from the TOP of the wave to the bottom

Electromagnetic waves are?

don't require a medium to travel (consist of magnetic/electric fields)

Newton's law #3

every action requires an equal or opposite action

What is gravity?

examples of forced (created by mass of objects)

What is bernoulli equation?

flow rate of a fluid through a pipe (depending on the energy of a fluid flowing through a pipe, height of pipe, and corresponding pressure)

What is power?

force applied over time (watts)

What is centripetal force?

force creates circular motion

What is work?

force exerted over a distance (measures in Joules)

What is pressure?

forced applied to a specific area (measured in pascals, atmospheres or bars)

What is free body diagram?

forces are drawn as vectors in the horizontal and vertical directions( can be added to find the total force)

What is the torque?

form of work applied in a circular motion

What is time?

given period (usually measured in meters per second)

Newton's law #2

greater the mass of the object being accelerated, the greater the amount of force needed to accelerate the object

What is distance?

how far something has traveled

What is a vector?

magnitude and direction

What is density of a material?

mass per unit volume

What is displacement? (d)

measure of how far an object has moved from its starting point (usually in meters)

What is circular motion?

movement of an object around central point

What is momentum (p)?

multiplying an object's mass by its velocity

Newton's law #1 aka "law of inertia"

object at rest will remain at rest object at motion will continue with the same speed and direction unless acted on by a force

What is potential energy?

object has the potential to do work

What is a wave?

periodic motion that carries energy through space/matter

What is centripetal acceleration?

points toward the center of the circle (keeps it on a circular path)

What is buoyancy?

(think of a boat) ability of object to float in a fluid (that has greater density than the object)

What is gravitational potential energy?

(when released) begins to move toward the earth & that potential energy becomes kinetic energy

A wave moves through its medium at 20m/s with a wavelength of 4m. What is the frequency of the wave? A. 5 s-1 B. 16 s-1 C. 24 s-1 D. 80 s-1

A (if you divide 20 by 4 you get 5)

What is speed ?

(also a scalar) distance traveled over the time the trip took

What is conduction?

(occurs when:) heat is transferred between neighboring molecules

A 5-kg block is suspended from a spring,, causing the spring to stretch 10 cm from equilibrium. What is the spring constant for this spring? A. 4.9 N/cm B. 9.8 N/cm C. 49 N/cm D. 50 N/cm

A

A transverse wave does NOT have______. A. compression B. amplitude C. frequency D. wavelength

A

A plucked guitar string makes 80 vibrations in one second. What is the period? A. 0.0125 s B. 0.025 s C. 0.125 s D. 0.25 s

A (1/80=0.0125)

A 1,000-kg car drives at 10 m/s around a circle with a radius of 50 m. What is the centripetal acceleration of the car? A. 2 m/s ^2 B. 4 m/s ^2 C. 5 m/s ^2 D. 10 m/s ^2

A (100/5=2m/s squared)

a 3-volt flashlight uses a bulb with 60-ohm resistance. What current flows through the flashlight? A. 0.05 amp B. 0.5 amp C. 1.8 amp D. 18 amp

A (3 divided by 60)

2 objects attract each other with a gravitational force of 12 units. If you double the distance between the objects, what is the new force of attraction between the two? A. 3 units B. 6 units C. 24 units D. 48 units

A (If you have 2 objects and double the distance 2+2=4 then 12 units divide by 4=3)

An object has a constant velocity of 50 m/s and travels for 10s. What is the acceleration of the object? A. 0 m/s2 B. 5 m/s 2 C. 60 m/s 2 D. 500 m/s 2

A (an object that has a constant, velocity does not experience any acceleration. Change in velocity is needed to calculate acceleration)

You drop a 50-g metal cube into a cylinder of water. How can you use displacement to find the density of the cube? A. Measure the volume of the displaced water & divide that into 50. B. Measure the volume of the displaced water & divide it by 50 C> Measure the mass of the displaced water & multiply it by 50 D. Measure the mass of the displaced water & divide it by 50.

A (density =mass/volume measuring the volume of the displaced water gives you the volume of the cube, and dividing that volume gives you the mass. 50 gives you the cubes density. "Displacement=how far an object has moved from its starting point)

A ball is dropped from a building with a height of 20 m. If there is no air resistance, how long will it take the ball to reach the ground? ( g=9.8 m/s^2) A. 2 s B. 4 s C. 5 s D. 10 s

A (divided 20 by 9.8 and get 2.04)

Which property of a substance does not change with a change in temperature? A. mass B. volume C. phase D. solubility

A (for B, C, & D heat can change their phase from liquid to gas, and change its volume)

100 N-m of work is done over 20 m. What force was applied to the object that was moved? A. 5 N B. 80 N C. 120 N D. 2,000 N

A (formula to use is : (A) W= Fd so the work is 100 divide it by 20 =5)

A 60-watt lightbulb is powered by a 110-volt power source. What is the current being drawn? A. 0.55 amperes B. 1.83 amperes C. 50 amperes D. 6,600 amperes

A (if you divide 110 by 60 you get around 0.55)

A 5-cm candle is placed 20 cm away from a concave mirror with a focal length of 15 cm. About what is the image height of the candle in the mirror? A. 30.5 cm B. 15.625 cm C. -15cm D. -30.5 cm

C

An electromagnet is holding a 1,500-kg car at a height of 25m above the ground. The magnet then experiences a power outrage, & the car falls to the ground. Which of the following is false? A. The car had a potential energy of 367.5 kJ B. 367.5 kJ of potential energy is converted to kinetic energy C. The car retains potential energy of 367.5 kJ when it hits the ground. D. The car's potential energy converts to kinetic energy & then to sound energy.

C

If the force on an object is doubled, how does its acceleration change? A. remains the same B. halved C. doubled D. eliminated

C

Which of the following describes a vector quantity? A. 13 miles B. 13 miles per hour C. 13 miles south D. 13 miles more

C ( vector means having direction (south) and magnitude (miles))

How do a scalar quantity and a vector quantity differ? A. a scalar quantity has both magnitude & direction , & a vector does not B. a scalar quantity has direction only, & a vector has only magnitude C. A vector has both magnitude & direction, & a scalar quantity has only magnitude D. a vector has only direction, & a scalar quantity has only magnitude

C (a vector quantity has both magnitude & direction. & a scalar only has magnitude)

A 1.0-kg block on a table is given a push so that it slidse along the table, if the block is accelerated at 6 m/s^2 , what was the force applied to the block? A. 0 N B. 3 N C. 6 N D. The answer cannot be determined from the information given.

C (according to newtons law, requires a 6n force)

When a car is driven for a long time, the pressure of air in the tire increase. This is est explained by which of the following gas laws? A. boyles law B. charles law C. gay-lussacs law D. daltons law

C (heat from the road can cause friction in the tires, which increases temp. of air in tire. A. constant temp for fixed mass B. law of volumes D. gases)

Why does potential energy increase as particles approach each other? A. Attractive forces increase B. attractive forces decrease C. repulsive forces increase D. repulsive forces decrease

C (unlike charges attract, like charges repel. As the near each other work is required & potential energy increases)

What is the kinetic energy of a 500-kg wagon moving at 10m/s? A. 50 J B. 250 J C. 2.5 x 10^4J D.5.0 x 10^5 J

C (use formula KE=1/2m (v^2) where m=mass and v=speed 1/2 (500x100) which = 2.5 x 10^4J)

When a junked car is compacted, which statement is true? A. Its mass increases. B. Its mass decreases. C. Its density increases. D. Its density decreases.

C. ( the mass of the car does not change, but once it is compacted there is an increase in density)

Marilyn is driving to a wedding. She drives 4 miles south before realizing that she left the gift at home. She makes a U-turn, returns home to pick up the gift, and sets out again driving south. This time, she drives 1 mile out of her way to pick up a friend. From there, they continue 5 miles more to the wedding. Which of these statements is true about Marilyn's trip? A. The displacement of her trip is 6 miles, and the distance traveled is 6 miles. B. The displacement of her trip is 14 miles, and the distance traveled is 14 miles. C. The displacement of her trip is 8 miles, and the distance traveled is 14 miles. D. The displacement of her trip is 6 miles, and the distance is traveled 14 miles.

D

A 110-volt appliance draws 2.0 amperes. How many watts of power does it require? A. 55 B. 108 C. 112 D. 220

D (110 x 2.0=220)

A 2,000-kg car travels at 15m/s. For a 1,500-kg car traveling at 15 m/s to generate the same momentum which would need to happen? A. it would need to accelerate to 20 m/s B. it would need to add 500-kg in mass C. both A & B D. either A or B

D (2,000x15=30,000 1,500x15=22,500 so it would need to accelerate 20 or gain 500 to equal the two )

Given the four wires described here, which would you expect to have the greatest resistance? A. 1 km of american wire gauge 1; diameter 7.35 mm B. 1 km of american wire gauge 2; diameter 6.54 mm C. 1 km of american wire gauge 3; diameter 5.83 mm D. 1 km of american wire gauge 4; diameter 5.19 mm

D (given four wires of the same length & material, the thinnest wire would have the highest resistance.)

A car travels 3 miles north, 6 miles south, 2 miles east, 2 miles west, & then 3 miles north. Which of the following is true? A. The displacement of the car is 16 miles, & the distance traveled is 0 miles. B. The displacement of the car is 16 miles, & the distance traveled is 16 miles. C. The displacement of the car is 0 miles, & the distance traveled is 0 miles. D. The displacement of the car is 0 miles & the distance traveled is 16 miles.

D (if you add up all the miles it is 16 but if you follow the directions you end up back where you started)

A transverse wave transports energy from North to South. In what direction do the particles in the medium move? A. only N to S B. Both N and S C. Only E to W D. both E & W

D (you can rule out A & B because particle action will always go perpendicular in transverse waves)

What is amperes?

Unit of electric current equal to flow of one Coulumb per second

What is solubility?

ability for a given substance (solute) to dissolve in a solvent

What is mass? (m)

amount of matter in an object (usually in kilograms)

What is temperature?

average kinetic energy of the atoms/molecules of a substance (higher the temp more kinetic energy)

What are longitudinal waves?

cause particles to vibrate parallel to movement of the wave

What is transverse waves?

cause particles to vibrate perpendicular to the movement of the wave

What is impulse?

change in momentum (measured in Newton seconds N`s)

What is acceleration (a)?

change in velocity over time (usually measured in meters per second squared)

What is electrical force?

created by charged particles

What is tension?

created by hanging a mass from a string or chain

What is friction?

created by movement of two surfaces in contact with each other

What is Ohm's Law?

current & resistance are inversely related, both are proportional to voltage (constant R)

What is period? (waves)

time it takes the wave to complete one oscillation (usually in seconds)

What is heat?

transfer of energy between substances

What is mechanical waves?

travel through a physical medium (ripples in a pond)

What is rotational motion?

using a similar set of variables & equations to those used for linear motion

What is kinetic energy?

when an object is in motion