Quiz Physics For Civil Engineering

Which of the following properties must be known in order to calculate the amount of heat needed to melt 1.0 kg of ice at 0ºC?

I. The specific heat of water

II. The latent heat of fusion for water

III. The density of water

• I only

• I and II only

• I, II, and III

• II only

Which of the following is an example of convection?

• The heat of the sun warming our planet

• The heat from an electric stove warming a frying pan

• A microwave oven cooking a meal

• An overhead fan cooling a room

A heat engine produces 100 J of heat, does 30 J of work, and emits 70 J into a cold reservoir.

What is the efficiency of the heat engine?

• 100%

• 70%

• 40%

• 30%

A person sips a drink through a straw. At which of the following three positions is the pressure lowest?

I. Inside the person’s mouth

II. At the surface of the drink

III. At the bottom of the drink

• only at position I

• only at position II

• only at position III

• both at positions I and II

Brian saves 2-liter soda per bottles so that he can construct a raft and float. If Brian has a mass of 80 kg, what minimum number of bottles is necessary to support him? The density of water is 1000 kg/m^3, and 1000 L = 1 m^3.

• 1600 bottles

• 800 bottles

• 40 bottles

• 4 bottles

A pirate ship hides out in a small inshore lake. It carries twenty ill-gotten treasure chests in its hold. But lo, on the horizon the lookout spies a gunboat. To get away, the pirate captain orders the heavy treasure chests jettisoned. The chests sink to the lake bottom. What happens to the water level of the lake?

• The water level drops.

• The water level rises.

• The water level does not change.

• The water level equal to the wight of the ship

While parking your car on a crowded street, you accidentally back into a steel post. You pull forward until the car no longer touches the post and then get out to inspect the damage. What does your rear bumper look like if the strain in the impact was the bumper will have sprung back to its original shape (although the paint may be scratched).

• Less than at the proportional limit

• greater than at the yield point, but less than at the fracture point

• greater than at the fracture point

• Less than the proportional limit

While parking your car on a crowded street, you accidentally back into a steel post. You pull forward until the car no longer touches the post and then get out to inspect the damage. What does your rear bumper look like if the strain in the impact was the bumper will be torn or broken.

• less than at the proportional limit

• greater than at the yield point but less than at the fracture point

• greater than at the fracture point

• greater than the proportional limit

Which the density is 2.5x 10^3 kg/m^3

• mass 2560kg, volume 0.64m^3

• mass 2560kg, volume 1.28m^3

• mass 8kg, volume 3.2x10^-3m^3

• mass 8kg, volume 1.6x10^-3m^3

Mercury is less dense at high temperatures than at low temperature. Suppose you move a mercury barometer from the cold interior of a tightly sealed refrigerator to outdoor on a hot summer day. You find that the column of mercury remains at the same height in the tube. How was the air pressure inside the refrigerator is compared with the air pressure outdoor?

• higher

• lower

• the same (ignore the very small change in the dimension of the glass due to the temperature change.

• Equal initially but changing