NamePer
AP Physics Daily Problem #161
The physics classroom measures 30 feet by 30 feet by 10 feet.
Determine the volume of the room in metric units:
Determine the mass of the air filling the room. Assume a temperature of 0C and one atmosphere pressure.
Would you be justified in neglecting the compressibility of air in this problem? Why?
AP Physics Daily Problem #162
A diver leaps into a 4-meter deep swimming pool and sinks to the bottom.
What is the change in pressure experienced by the diver?
What is the absolute pressure at the surface of the pool and the bottom of the pool?
Is this change significant compared to the atmospheric pressure present at the surface?
Would the pressure change be different if the pool were filled with gasoline (yeech!)
AP Physics Daily Problem #163
A force of 100 pounds is applied to a brake pedal which is attached to a master cylinder with a piston of 2.0cm diameter via a 4:1 lever system. The master cylinder pressure is conducted to a brake caliper cylinder whose piston is 6cm in diameter.
Determine the force applied to the master cylinder piston in Newtons.
Determine the pressure in the brake fluid in Pascals.
Determine the force that the caliper piston exerts on the brake pad in Newtons.
If the brake pad has a coefficient of friction of 0.4, determine the braking force that can be applied to a brake disk. Consider only this one single brake pad.
AP Physics Daily Problem #164
A cube of material 10cm on a side is submerged in a tank of water It has a density of 3.0x103 kg/m3.
What is the weight of the cube before it is submerged?
What will the buoyant force be on the cube after it submerged?
What is the weight of the cube after it is submerged?
Would the weight of the cube be greater or less if the fluid was gasoline instead of water? Explain why in terms of Archimedes’ principle
AP Physics Daily Problem #165
A ½-meter stick of cross section 7.0mm by 25.0mm and mass 37g is placed vertically in a graduated cylinder of water and allowed to float freely.
Determine the density of the meter stick.
Determine how much of the meter stick will be submerged when it floats freely. (Hint: figure out the weight of the meter stick and use Archimedes’ principle.
How much force must be applied to the meter stick to force its entire length underwater?
A lead weight is carried in a toy boat floating in water in a fish tank. The level of the water in the tank is marked, then the weight is thrown overboard into the water where it sinks to the bottom. Did the water level on the side of the tank rise or fall? Explain why! Think!!
AP Physics Daily Problem #166
A rectangular barge constructed of steel is 30m wide and 100m long. After it is launched, it draws (sinks into) 3.0m of water.
Determine the mass of the barge.
If the river on which the barge will be used has a minimum depth of 10m, how much cargo (in terms of mass) can be loaded onto the barge?
Would it make any difference if the barge were in salt water? Answer the qualitatively, but explain your answer fully.
Determine the pressure against the bottom of the barge when it is fully loaded in fresh water.
AP Physics Daily Problem #167
Mr. Lyle’s classroom measures 10m by 10m by 2.5m. The air in the classroom is replaced by the ventilation system in 8 minutes. Air flows in through two ducts each measuring 15cm by 60cm.
What is the velocity of the air in each duct in m/s?
What is the mass rate of flow of air into the room in kg/s.
Assume that the air coming from one duct impinges on a flat plate and exits equally in all directions parallel to the plate. Use momentum methods to determine the force on the plate. ..
AP Physics Daily Problem #168
A pipe springs a leak, which causes a stream of water to rise 8.0 meters into the air.
What is the minimum pressure within the pipe?
Determine the velocity of the stream at the leak.
If the hole is 1.0cm in diameter, determine the mass rate of flow through the leak
AP Physics Daily Problem #169
Water moves into a pipe of cross sectional area 0.5m2 at a rate of 10m/s. at a pressure of 10,000kPa
Determine the mass rate of flow of the water
The duct necks down to a cross-sectional area of 0.2m2.
Determine the velocity in this cross-section
Determine the pressure in this cross-section.