PHY 1151 EXAM 1

50 g of ice at 0oC is added to 50 g of liquid water at 0oC in a well-insulated container, also at 0oC. After a while, the container will hold

50 g of ice, 50 g of liquid water.

1 mol of air has an initial temperature of 20oC. 200 J of heat energy are transferred to the air in an isochoric process, then 200 J are removed in an isobaric process. Afterward, the air temperature is

> 20 C

Water flows through a pipe having a varying width. More water flows per second through the wide section than through the narrow section because there is more room for it to flow

F

A gas in a container expands rapidly, pushing the piston out. The temperature of the gas

Falls.

"Tensile strain" is the applied force per cross-sectional area

False

A 50cm3 block of wood is floating partially submerged in water and a 50 cm3 block of iron is totally submerged in water. The block of wood has a greater buoyant force on it

False

As a solid melts, its temperature increases

False

If you double the pressure on the surface of a can of water, the buoyant force on a stone placed in that water will increase

Falsw

If the volume of a sealed container of gas is decreased, the gas temperature

Not enough information to tell.

In an isothermal expansion

Q>0

Heat is the energy that flows due to a temperature difference

T

Two identical cylinders, A and B, contain the same type of gas at the same pressure. Cylinder A has twice as much gas as cylinder B. Which is true?

TA<TB

Heat energy can be transferred from a cold reservoir to a hot reservoir only if an external agent does work on the system

True

The net change in thermal energy for a single cycle of a heat engine is always zero

True

In an isothermal expansion,

W<0 and Ws >0

A gas in a container expands rapidly, pushing the piston out. The temperature of the gas falls. This is because

Work is done

Dragging an object across a rough surface makes it warm, or even hot. The temperature increase occurs because of

Work.

When you blow some air above the upper face of a paper strip, the paper rises. This occurs because

the air above the upper face of the paper moves faster, which makes the pressure lower than at the lower face