Physics Quantum Mechanics Level: High School
A hydrogen atom consist of a proton and an electron. However, if a negatively charged muon is substituted for the electron a hydrogen-like atom can be formed from a proton and negatively charged muon . The muon mass is m muon = 206 me-.a) How do the energies of the first three levels compare to the hydrogen atom ?
b) What is the most probable distance from the proton for the 1s and 2p0 levels of this atom and the hydrogen atom ?
Physics Heat & Thermodynamics Level: High School
Thermal Expansion
A copper rod of diameter 2.0034 cm is cooled so that it fits into a circular hole of exactly 2.000 cm . How much doe the rod need to be cooled (in Celsius ) ?
Physics Force & Laws Of Motion Level: High School
Friction
The two blocks are connected by a light string that passes over a frictionless pulley with a negligible mass . The 3 kg block lies on a rough horizontal surface with a constant coefficient of kinetic friction 0.1 . The hanging block has a mass of 6 kg. The system starts from rest . The acceleration of gravity is 9.8 m/s2 . What is the speed of the 6 kg hanging mass when it has fallen a height 9 m ? Answer in units of m/s .
Physics Work,Power & Energy Level: High School
Conservation of Energy
A block with mass m starting from rest at point A is sliding down a rough incline with kinetic coefficient of friction mu . The incline has angle theata with respect to the horizontal surface . As the block slides down for a distance s , it passes point B . Find the kinetic energy of the block as it passes B .1) KB = mg s sin theata-mu mg s sin theata
2) KB = mg s cos theata + mu mg s cos theata
3) KB = mg s cos theata + mu mg s sin theata
4) KB = mg s sin theata + mu mg s cos theata
5) KB = mg s sin theata – mu mg s cos theata
Physics Work,Power & Energy Level: High School
Conservation of Energy
A 2.99 g bullet moving at 258 m/s penetrates a tree to a depth of 6.12 cm . Use energy consideration to find the average frictional force that stops the bullet . Answer in units of N .
Physics Work,Power & Energy Level: High School
Conservation of Energy
A 11 kg child on a playground swing moves with a speed of 9.4 m/s When the 1 m long swing is at its lowest point . The acceleration of gravity is 9.81 m/s2 . What is the angle that the swing makes with the vertical when the swing is at its highest point ? Answer in units of degrees .
Physics Work,Power & Energy Level: High School
Conservation of Energy
A child slides without friction from a height of 10.2 m above the water along a curved water slide , as shown below . She is launched from a height 5.9 m above the water at an angle of 51 degrees above the horizontal toward a pool . The acceleration of gravity is 9.81 m/s2 . Determine her maximum airborne height above the water . Answer in units of m .
Physics Work,Power & Energy Level: High School
Conservation of Energy
A block of mass 0.34 kg placed on a vertical spring of constant 2657 N/m and pushed downward, compressing the spring 0.13 m . After the block is released it leaves the spring and continues to travel upward . The acceleration of gravity is 9.8 m/s2 . What height above the point of release will the block reach if air resistance is negligible ? Answer in units of m .
Physics Work,Power & Energy Level: High School
Conservation of Energy
Consider a frictionless roller coaster. Passenger cars starts at point C with zero initial speed , accelerate as they go down, swing around a circular vertical loop, then go on towards further adventures. When a car goes through the top of the loop (point B), the passengers feel weightless (for just a moment) What is the height h of the starting point C ?1) h = (3/4) R
2) h = (7/2)R
3) h = 3R
4) h = 2R
5) h = R
6) h = (7/3)R
7) h = (1/4)R
8) h = (1/3)R
9) h = (5/2)R
10) h = (2/3)R
Physics Work,Power & Energy Level: High School
An elevator is rising at constant speed . Consider the following statements:i) The upward cable force is constant .
ii) The kinetic energy of the elevator is constant .
iii) The gravitational potential energy of the earth-elevator system is constant.
iv) The acceleration of the elevator is zero.
v) The mechanical energy of the earth-elevator system is constant .
Which of the following statement are true ?
1) only i, ii and iii are true .
2) only, ii and v are true
3) All fiver are true
4) only i, ii and iv are true .
5) only iv and v are true .
Physics Work,Power & Energy Level: High School
Conservation Of Energy for a Spring
A pinball machine launches a 99 g ball with a spring-driven plunger . The game board is inclined at 8 degrees above the horizontal . Assume: The plunger’s mass and frictional effects are negligible. The acceleration of gravity is 9.8 m/s2 . Find the force constant k of the spring that will give the ball a speed of 97 cm/s when the plunger is released from rest with the spring compressed 3 cm from its relaxed position . Answer in units of N/m .
Physics Misc Topic Level: Misc Level
Conservation Of Energy
The pendulum bob is released from at a height below the height of the peg . A pendulum made of a string of length 11 m and a spherical bob of mass 5.4 kg and negligible radius swings in a vertical plane . The pendulum is released from an angular position 47 degrees from vertical as shown in the figure at “click here” . The string hits a peg located a distance 4m below the point of suspension and swings about the peg up to an angle on the other side of the peg. Then , the bob proceeds to oscillate back and forth between these two angular positions . The acceleration of gravity is 9.8 m/s2 . What is the maximum angle which the pendulum will swing to the right after hitting the peg ? Answer in units of degrees .
Physics Misc Topic Level: Misc Level
Conservation Of Energy
The pendulum bob is released from at a height below the height of the peg . A pendulum made of a string of length 11 m and a spherical bob of mass 5.4 kg and negligible radius swings in a vertical plane . The pendulum is released from an angular position 47 degrees from vertical as shown in the figure at “click here” . The string hits a peg located a distance 4m below the point of suspension and swings about the peg up to an angle on the other side of the peg. Then , the bob proceeds to oscillate back and forth between these two angular positions . The acceleration of gravity is 9.8 m/s2 . What is the maximum angle which the pendulum will swing to the right after hitting the peg ? Answer in units of degrees .
Physics Work,Power & Energy Level: High School
Conservation Of Energy
A mass m is released from a height h above the ground , It is given an initial horizontal velocity of magnitude v0 . What is the speed of the mass when it hits the ground ?1) v = square root (2gh)
2) Undetermined , since we don’t know the angle at which the mass hits the ground.
3) v = square root (v0 squared + 2gh)
4) v = square root(gh/2)
5) v = square root ((v0 squared/2)+gh)
6) v = square root ((v0 squared/2)+9gh/2)
7) v = square root (v0 squared + (gh/2))
8) v= square root (gh)
9) v = square root (v0 squared + gh)
Physics Work,Power & Energy Level: High School
Elastic Potential Energy
An ore car of mass 43000 kg starts from rest and rolls downhill on tracks from a mine . At the end of the tracks , 7.7 m lower vertically , is a horizontally situated spring with constant 490000 N/m . The acceleration of gravity is 9.8 m/s2 . Ignore friction . How much is the spring compressed in stopping the ore car ? Answer in units of m .