12, 13 and set 6 questions

When a rigid object rotates about a fixed axis, what is true about all the points in the object? A) same angular speed B) same tangential speed C) same angular acceleration D) same tangential acceleration E) same radial acceleration

A&C) same angular speed and angular acceleration

A 10-kg piece of aluminum sits at the bottom of a lake, right next to a 10-kg piece of lead, which is much denser than aluminum. Which one has the greater buoyant force on it? A) the aluminum B) the lead C) Boht the same buoyant force. D) It cannot be determined without the volume being known.

A) Aluminum

When a car goes around a banked circular curve at the proper speed for the banking angle, what force cause it to follow the circular path? A) the normal force from the road B) the friction force from the road C) gravity

A) the normal force from the road

When a gas expands adiabitically, A)the internal(thermal) energy of the gas decreases B) the internal(thermal) energy of the gas increases C)it does no work D)work is done on the gas

A)the internal(thermal) energy of the gas decreases

A boat loaded with rocks is floating in a swimming pool. If the rockets are thrown into the pool, the water level in the pool, after the rocks have settled to the bottom, A) rises B) falls C)stays the same

B) falls

By what primary heat transfer mechanism does the sun warm the earth? A)convection B)Radiation C)All of the above

B)Radiation

An ideal gas is compressed isobarically to one-third of its initial volume. The resulting pressure will be: A) three times as large as the initial value B) equal to the initial value C)more than three times as large as the initial value

B)equal to the initial value

Salt water is denser than fresh water. A ship floats in both fresh water and salt water. Compared to the fresh water, the volume of water displaced in the salt water is A)more. B)less. C)same D)cannot be determined because we don't know the volume of the ship

B)less

When you blow some air above a paper strip, the paper rises. This happens because: A)the air above the paper moves faster and the pressure is higher B)the air above the appear moves faster and the pressure is lower C)the air above the paper moves faster and the pressure remains constant D)the air above the paper moves slower and the pressure is higher E)the air above the paper moves slower and the pressure is lower

B)the air above the paper moves faster and the pressure is lower.

When a car goes around a circular curve on a horizontal road at constant speed, what force causes it to follow the circular path? A)the normal force from the road B)the friction force from the road C)gravity D)No force

B)the friction force from the road

Which one of the following quantities is the smallest unit of heat energy? A)calorie B) kilocalorie C)joule

C)Joule Joule>Calorie>Kilocalorie

As a rock sinks deeper and deeper into water of constant density, what happens to the buoyant force on it if it started above the surface of the water? A)The buoyant force keeps increasing steadily. B)The buoyant force remains constant. C)The buoyant force first increases and then remains constant. D)The buoyant force steadily decrease.

C)The buoyant force first increases and then remains constant

When an object moves in the uniform circular motion, the direction of its acceleration is: A)in the same direction as its velocity vector B)in the opposite direction of its velocity vector C)is directed toward the center of its circular path

C)is the directed toward the center of its circular path

A wooden block contains some nails so that its density is exactly equal to that of water. If it is placed in a tank of water and released from rest when it is completely submerged, it will: A) rise to the surface B) sink to the bottom C)remain where it is released

C)remains where it is released

The absolute temperature of an ideal gas is directly proportional to which of the following quantities? A)the average speed of its molecules B)the average momentum of its molecule C)the average kinetic energy of its molecules D)the mass of its molecules E)It is proportional to all of the above quantities

C)the average kinetic energy of its molecule

ON a cold day, a piece of metal feels much colder to the touch than a piece of wood. This due to the difference in which one of the following physical properties of these materials? A)density B)specific heat C)thermal conductivity D)mass

C)thermal conductivity---have good bonds specific heat---amount of heat raises temperature of 1 kg substance by 1 K

Consider a flat steel plate with a hole through its center, When the temperature of the plate is increased, the hole will: A)expand only if it takes up more than half of the plates surface area B)contract if intakes up less than half of the plates surface area C)always contract as the plate expands into it D)always expand with the plate

D)always expand with the plate

Oxygen molecules are 16 times more massive than hydrogen molecules. At a given temperature, the average molecular kinetic energy of oxygen molecules, compared to that of hydrogen molecules, A) is greater B) is less C) is the same

D)is the same

Consider a brick that is totally immersed in water, with the long edge of the brick vertical. The pressure on the brick is: A) the same on all surfaces of the brick B) greatest on the face with largest area C)greatest on the top of the brick D)greatest on the sides of the brick E)greatest on the bottom of the brick

E) greatest on the bottom of the brick

There must be equal amounts of mass on both sides of the center of the mass. T/F

F

Substance A has a density of 3 g/cm3 and substance B has a density of 4 g/cm3. In order to obtain equal mass of these 2 substances, what must be the ration of the volume of A to the volume of B? a)1/3 b)4/3 c)3/4 d)3/1

b) 4/3 -