Arches work well in construction because (a)   . a. The entire structure is under tension b. The entire structure is under compression c. The compression and tension balance each other out.

If you have two differently-sized spheres of metal and they have the same mass, then (a)   . a. The smaller sphere is denser b. Their densities are proportional to their sizes c. The larger sphere is denser d. They have the same density as well

Compared to smaller animals, larger animals have a ________. a. similar ratio of surface area to weight b. smaller ratio of surface area to weight c. larger ratio of surface area to weight d. The pressure under 100 feet of salt water is closest to ________.

(a)  

When a boat is floating in the water, (a)   . a. the buoyant force is greater than the weight of the boat b. the buoyant force equals the mass of the boat c. the buoyant force equals the weight of the boat d. the volume of displaced water equals the volume of the boat

.Pressure can be increased by (a)   . a. increasing the area or decreasing the force b. taking more time to relax c. raising both the force and the area by proportional amounts d. increasing the force or decreasing the area

In a hydraulic press (hydraulic lever), if the force is multiplied by a factor of 20, (a)   . a. the pressure is also multiplied by a factor of 20 b. the distance is divided by a factor of 20 c. the distance is also multiplied by a factor of 20 d. the product of force x distance is also multiplied by 20

If a tire pressure gauge reads 30 PSI, the actual absolute pressure in the tire is closest to (a)   . a. 150 kPa b. 45 PSI c. 90 mmHg d. 15 PSI

If the pressure in a gas is multiplied by a factor of 6 and the temperature is multiplied by a factor of 3, the volume of the gas will be (a)   the original volume. a. three times b. twice c. one half of d. one third of

Bernoulli's Principle states that, as the velocity of a fluid increases, (a)   . a. the temperature of the fluid will also increase b. the volume of the fluid will decrease c. the pressure in the fluid will decrease d. the pressure in the fluid will also increase

In a plasma, the (a)   . a. atoms are broken down into molecules b. protons are separated from the neutrons c. electrons are separated from the nuclei d. isotopes are separated by charge

Ninety nine percent of our atmosphere is contained in a layer about (a)   thick. a. 30 miles b. 10 miles c. 40 miles d. 20 miles

Earth's atmosphere is composed primarily of (a)   .

Compared to an increase in temperature of 20 Fahrenheit degrees, an increase in temperature of 20 Celsius degrees is (a)   . a. the same b. smaller c. larger

A material with a low specific heat will tend to (a)   . a. cool down quickly but heat up slowly b. heat up and cool down quickly c. heat up quickly but cool down slowly d. heat up and cool down slowly

Compared to a cup of hot coffee, a bathtub full of lukewarm water has (a)   . a. lower internal energy and lower average molecular energy b. higher average molecular energy but lower internal energy c. higher internal energy but lower average molecular energy d. higher internal energy and higher average molecular energy

Heat is defined as (a)   .

The lower the temperature of an object, the (a)   the wavelength of electromagnetic radiation it emits

If a window is perfectly sealed (no air leaks), heat can still penetrate via (a)   .

If you touch a wooden pencil and a metal pen that have both been sitting on your desk, the pen feels cooler because (a)   .

The longer the wavelength of electromagnetic radiation, the (a)   the frequency.

Global warming due to the Greenhouse Effect (a)   . a. was first discovered by Al Gore in the early 1970's b. is a Chinese hoax designed to take away our jobs c. may actually be due to ash and other contaminants from volcanos d. can happen on any planet with an atmosphere

When water vapor condenses into liquid water, it (a)   . a. must pass through a solid phase b. transfers heat to the liquid water with no net heat flow to the environment c. absorbs heat from the environment d. releases heat to the environment

Clouds and fog are caused by (a)   . a. evaporating liquid water b. burning too many fossil fuels c. condensing water vapor d. vapor deposition in the atmosphere

In a standard air conditioner or heat pump, the refrigerant ________ outside and ________ inside.

(a)  

In a pressure cooker, the food is cooked faster than in a normal pot because (a)   . a. the increased pressure breaks down the food molecules faster b. the water boils at a higher temperature c. the lower pressure breaks down the food molecules faster d. the water boils at a lower temperature

In a standard refrigerator, it is the (a)   that is most responsible for the transfer of heat. a. latent heat of refrigeration b. latent heat of fusion c. latent heat of vaporization d. latent heat of sublimation

Absolute zero is approximately (a)  

Normal room temperature is closest to (a)   .

When a gas is compressed, (a)   . a. its internal energy will decrease b. its internal energy will increase c. the gas will expand d. internal energy will flow out of the gas

If heat flows into a system, (a)   . a. the system will be able to do more work b. the system will be able to do less work c. the work capacity of the gas is not affected

a cannon recoils while firing a cannonball. The speed of the cannon's recoil is relatively small because the (a)   . a. momentum is mainly concentrated in the cannonball b. force against the cannon is smaller than against the ball c. momentum of the cannon is smaller d. cannon has much more mass than the cannonball

Truck A comes to a stop from 20 m/s by crashing into a haystack. Truck B comes to a stop from 20 m/s by crashing into a brick wall. Both trucks have the same mass. Compared to truck A, the impulse on truck B during the collision is (a)   . a. larger b. more concentrated c. the same d. smaller

Automobile safety devices like padded dashboards and airbags work by (a)   . a. decrease average impulse by distributing it over a larger distance b. decreasing average force by extending the time of the collision c. decreasing average force by shortening the time of the collision d. decreasing the change in momentum involved

You drop a blob of clay and a golf ball of equal mass onto a hard surface. The clay sticks to the surface, while the golf ball bounces. Compared to the impulse on the clay, the impulse on the golf ball is (a)   . a. smaller b. zero because the forces cancel out c. larger d. the same

A 1000 kg automobile is pushed a distance of 20 m with a force of 2500 N. The work done on the automobile is (a)   . a. 50 MJ b. 200 kJ c. 500 kJ d. 50 kJ

A 1000 kg automobile is pushed a distance of 20 m with a force of 2500 N. The speed of the car at the end of the 20 m will be (a)   . a. 5 m/s b. 25 m/s c. 40 m/s d. 10 m/s

The primary energy source of the Earth is (a)   . fossil fuels geothermal energy radioactive elements in the core the sun

A 100 kg student carrying 25 kg of pumpkins runs up a 10 m high flight of stairs in 20 seconds. The average power exerted by the students during this time is (a)   . Correct! 625 W 125 W 1250 W 12.5 kW

A 60 W light bulb puts out 15 W of light and 45 W of heat. The efficiency of the bulb is (a)   . 15% Correct! 25% 45% 60%

When an ice skater wants to spin quickly, he will often pull his arms in close to his body. This results in (a)   . a larger angular momentum a smaller rotational speed a smaller angular momentum Correct! A smaller rotational inertia

If you swing a ball on a string around your head in a circular motion at constant speed, (a)   . the net force on the ball is zero Correct! the string provides the centripetal force the centripetal force and the centrifugal forces cancel out the string provides the centrifugal force

To turn a screw that is attached very tightly, it is best to use a screwdriver with a (a)   . Correct Answer wide handle long blade smooth handle You Answered long handle

In order for an object to be in equilibrium, the Center of Mass must be located (a)   . as high as possible in the object vertically above the Center of Gravity horizontally level with the base of support Correct! vertically above the base of support

If you are standing on a rotating platform (like a Merry-Go-Round), the further out from the center you stand, (a)   . Correct! the greater your tangential speed the greater your rotational speed the greater your angular speed the longer it will take you to go around once

If you triple the distance between two objects, the gravitational force between them will be (a)   the original value. Correct! 1/9 of 3 times 1/3 of 9 times

If the mass of the Earth and the mass of the Moon were to both suddenly double, the gravitational force between them would (a)   . double stay the same still be balanced out by the centrifugal force between them Correct! quadruple

Astronauts in orbit around the Earth experience weightless conditions because (a)   . space does strange things to a person they are flying so fast as to overcome gravity Correct! they are in a state of free fall most orbits put them out of the reach of gravity

If a planet had one half of Earth's mass and one half of Earth's radius, the force of gravity on the surface of that planet would be (a)   Earth's surface gravity. four times one quarter of one half of Correct! Twice

A lunar month is about 27 days. If the moon were farther from Earth than it is now, the length of the lunar month would be (a)   . less than 27 days the same less regular than it is now Correct! more than 27 days

When a projectile with negligible air resistance is thrown at an upward angle, (a)   . neither the horizontal nor the vertical speed stays constant Correct! the horizontal speed stays constant the vertical speed stays constant both the horizontal and vertical speeds stay constant

In a circular satellite orbit, (a)   . the speed remains constant but the distance changes neither speed nor distance remain constant Correct! both the speed and distance remain constant the distance remains constant but the speed changes

In an elliptical orbit, (a)   . a satellite moves fastest when it is far from the central body Correct! a satellite moves fastest when it is near the central body the kinetic energy of the satellite remains constant the gravitational potential energy of the satellite remains constant

If a rocket is fired from Earth in a direction directly away from the Sun at a speed just above Earth's escape speed, the rocket will (a)   . Correct! end up orbiting the Sun eventually escape out solar system end up falling into the Sun burn up in the atmosphere