Physics Relativity Level: Misc Level
Suppose a person riding on top of a freight car shines a searchlight beam in the direction in which the train is traveling.Compare the speed of the light beam relative to the ground when; A) The train is at rest. B) The train is moving.How does the behaviour of the light beam differ from the behaviour of a bullet fired in the same direction from the top of the freight car?
Physics Heat & Thermodynamics Level: Misc Level
At 20.0 degrees Celius a copper disk is 10.00 cm in diameter and a hole in the disk is 0.4000 cm in diameter. what are the diameters of the disk and the hole at 200 degress Celius? The coefficient of the linear expansion of copper is 1.70x10^-5/(degrees Celius)
Physics Heat & Thermodynamics Level: Misc Level
A gas contains molecules made with two different atoms. Measurements of the specific heat give results as stated.From T (sub-1) to T (sub-2) Cv/R=11.5, from T (sub-2) to T (sub-3) Cv/R=2.5, from T (sub-3) to T (sub-(k) Cv/R=3.5 Describe the value of the three different results for Cv in the given temperature ranges as well as you are able to.
Physics Heat & Thermodynamics Level: Misc Level
A gas contains molecules made with two different atoms.Measurements of the specific heat give results as stated.From T (sub-1) to T (sub-2) Cv/R=31.5 from T (sub-2) to T (sub-3) Cv/R=2.5, from T (sub-3) to T (sub-(k) Cc /R=3.5 Describe the value of the three different results for Cv in the given temperature ranges as well as you areable to.
Physics Heat & Thermodynamics Level: Misc Level
A small meteorite comprised of iron with mass 1.32x10^3 kg enters Earths atmosphere from space and crashes into Lake Camplain (a body of fresh water, which has a total mass of 8.56x10^8 kg ).The entry into Earths atmosphere increases the temperatureof the meteorite to 3.24 x10^3 degrees celius just before it comes apart in small pieces and impacts he water at a speed of 3500 m/s above the deepest part of the lake.The temperature of the lake is a chilly 10 degrees celius just before the impact. what is the final temperature of the system of the lake and meteorite? For this purpose asume the lake bottom is a good thermal insulator.
Physics Semiconductors Level: Misc Level
In a doped semiconductor, the band gap is 0.078 eV. Compare the proportion of the charge carries in the semiconductor at room temperature and at 300 degrees celius.
Physics Heat & Thermodynamics Level: Misc Level
The air temperature over a lake is -10 degress Celius, while the water below the surface of the ice(now 1..00 cm thick) is at 4 degrees celius. What is the speed at which the ice layer on the lake thickens (measured in m/s or some multiple thereof ) ? Information you may need; The thermal conductivity of ice is 1.6 w/(mk), the specific heat of ice is 2000 J/(kg degrees Celius),that of water is 4186 J/(kg degrees celius) and the latent heat of fusion of water is 334 kJ /kg.
Physics Force & Laws Of Motion Level: Misc Level
A 12.1 kg concrete block rests on a horizontal table. The coefficient of kinetic friction between the block and the table is .37.A second block is attached to the concrete block by a string a string passing over a frictionless pulley of negligible mass. If the acceleration of the concrete block is .735 m/s2 to the right, what is the mass of the second block?
Physics Work,Power & Energy Level: Misc Level
Bobby accelerates from rest at 121 m/s2 for 1.2 seconds. He then runs along level ground at that speed until he jumps onto a stationary wagon fully loaded with large cement blocks. The wagon and the blocks have a total mass of 122 kg.(No friction involved in this problem. It,s a frictionless environment,) As the wagon, with Bobby on board, rolls along it encounters a hill inclined upward at 15 degrees. The wagon then rolls up the hill a distance of 11.3 m ( along the ground) before coming to a stop.Determine Bobby,s mass.
Physics Force & Laws Of Motion Level: Misc Level
A student has a 75 g crystal hanging by a string of negligible mass from the rearview mirror in her car.
a.Determine the angle the string makes with the vertical when she accelerates at a constant rate of .35 g ( maybe this is a typo and should be.35 m/s??)
b.Determine the tension in the string during this acceleration.
c. Construct a free body diagram of the crystal
Physics Force & Laws Of Motion Level: Misc Level
A 12.1 gram bullet is fired horizontally into a 24.0 cm thick wooden fence post at a point 155 cm above the ground with a speed of 430 m/s. The bullet then exits the post striking the ground 3509 cm from the base of the post.Determine the average resisting force exerted by the post on the bullet.
Physics Kinematics Level: Misc Level
Martha (a very fast cyclist )is riding her bike along a level, horizontal road when she unknowingly comes to a complete drop off (or cliff)at the end of the road. By remaining completely composed she lands perfectly on another level road exactly 121 m ahead and 18 m below and then continues on her way ( you may ignore air resistance).
a. Determine Martha ,s launce velocity along the original road (upon encountering the cliff).
b.Determine Martha,s total flight time.
c.Determine the velocity of Martha and her bike when she is exactly 12.5 m below the original road.
Physics Force & Laws Of Motion Level: Misc Level
A cat drops from a tree limb to the ground in a perfect vacuum and is observed to reach the ground in 24.2 seconds. Upon impact, the cat comes to rest without bouncing in .123 seconds.
a.Determine the velocity of the cat just prior to impact w/the ground.
b.Determine the height of the limb.
c.Determine the average acceleration of the cat during the impact(or collison).
d.Using your result from part C, determine the average jerk experienced by the cat during the collision with the ground.
Physics Waves And Oscillations Level: Misc Level
A ship mapping the depth of the ocean emits a sound of 38 kHz. The sound travels to the ocean floor and returns 0.68 s later,A .)How deep is the water ar that location? B.)What is the waverngth of the wave in water?C.) What is the waverength of the retiected wave as it traveis into the air. where the speed of sound is 350 m/s?
Physics Waves And Oscillations Level: Misc Level
A geoiogical survy ship mapping the floor of the ocean sends sound pulses down from the surface and measures the time taken for the echo to return.How deep is the ocean at a point wnere the echo time (down and back )is 7.07s7 The temperature or the seawater is 25 degree Ceisius.
