Physics Rotational Mechanics Level: High School
Rotational Equilibrium
Thee children are trying to balance on a seesaw , which consists of a fulcrum rock , acting as a pivot at the center , and a very light board 3.53 m long . Two boys are already on either end . The boy on the left has a mass of m1 = 43.0 kg , and the boy on the right has a mass of m2 = 36.5 kg . Where should the third child ,whose mass is m3 = 24.7 kg , place himself so as to balance the seesaw ? Distance are measured from the pivot with the positive direction to the right .a) -3.40 x 10^-1 m
b) 3.77 x 10^-1 m
c) -4.18 x 10^-1 m
d) 4.64 x 10^-1 m
e) -5.61 x 10^-1 m
Physics Rotational Mechanics Level: High School
Archimedes’s Principle
Five solid objects made of different material are placed in a tub of water .The objects are cubes made of wood . (SG = 0.5) , ice (SG = 0.92) , aluminum (SG = 2.7) ,steel (SG = 7.8) and gold (SG = 19.3) , All of the objects have the same mass . You hold the object on the bottom of the tub , Then you let the objects go .In the instant after release ,which of the following statements are true ?a) The aluminum cube would feel the least buoyant force .
b) The ice cube would move up with constant acceleration .
c) The ice cube would feel the greatest buoyant force .
d) The steel cube would displace the least water .
e) The would cube would displace its own volume in water .
Physics Work,Power & Energy Level: High School
Two equal mass balls (one red and other blue ) are dropped from the same height, and rebound of the floor . The red ball rebounds to a higher position than the blue ball . Neglect air resistance . Which one of the following statement is / are true about this statement .a) The red ball is subjected to the greater impulse during the collision with the floor .
b) Once they come to a stop in the air after bouncing off the floor , both balls have the same of potential energy .
c) Except for the instant they collide with the floor , both balls are in free fall .
d) During the collision with the floor , both ball transfer the amount of momentum to the floor .
e) Mechanical energy is conserved for both balls.
Physics Work,Power & Energy Level: High School
Conservation of Energy
A bullet (m = 0.025 kg) is fired with a speed of 95.0 m/s and hits a block (M = 2.80 kg) supported by a string . Find the height to which the block rises .a) 3.60 x 10^-2 m
b) 4.79 x 10^-2 m
c) 6.37 x 10^-2 m
d) 8.48 x 10^-2 m
e) 1.13 x 10^-1 m
Physics Work,Power & Energy Level: High School
Conservation of Energy
A 26.0 kg child slides down a long slide in a playground . She starts from rest at a height h1 of 18.0 m . When she is partway down the slide , at a height h2 of 5.00 m , she is moving at a speed of 7.90 m/s . Calculate the mechanical energy lost due to friction (as heat etc. )a) 1.02 x 10^3 J
b) 1.28 x 10^3 J
c) 1.60 x 10^3 J
d) 2.00 x 10^3 J
e) 2.50 x 10^3 J
Physics Current Electricity Level: High School
Combination of resistors
Find the equivalent resistance for all of the resistors in the figure at “click here” . The resistance is given in ohms .
Physics Current Electricity Level: High School
Combination of resistors
Find the current through each of resistors in the figure which is shown at “click here”
Physics Magnetism,Magnetic Effects Of Current Level: High School
Force on a moving charge in a magnetic field
Consider the 4 particles below traveling as shown in the figure at “click here” the magnitude field B . Notice the sign indicate if the force on the particle will be up , down, into the paper, out of the paper , or zero .
Physics Electrostatics Level: High School
Capacitor
Find the charge on each capacitor and the voltage across each capacitor .
Physics Magnetism,Magnetic Effects Of Current Level: High School
Torque on a coil in a magnetic field
Consider a square coil 1/10 meter on each side . A 2 amp current is flowing around the coil if B = 1.5 Tesla as shown in the figure at “Click here” . Two cases are shown . For each case .a) What is the flux .
b) What is the torque on the coil .
Physics Magnetism,Magnetic Effects Of Current Level: High School
Force on a moving charge in a magnetic field
A proton travels with a speed of 3 x 10 6 m/s at a 90 degree angle with a magnetic field of .3 Tesla (field points in the +y direction)a) What is the magnitude of the force on the proton ?
b) If the angle were changed from 90 degrees to 37 degrees , what is the magnitude of the force on the proton ?
Physics Force & Laws Of Motion Level: High School
Newton’s Third Law
Here on earth can you suggest a simple demonstration to show how the mass of fuel on board a spaceship can move the craft forward as the fuel burns out the back of the craft ?
Physics Gravitation Level: High School
Orbital Motion
What would happen to the moon if something took away its orbital velocity ? What would happen is something took away the Earth’s gravitational field ?
Physics Gravitation Level: High School
The earth attracts the noon gravitationally , and the moon likewise attracts the earth, each pulling on one another according to Newton’s third law of motion . Is there some point between the earth and moon where the net gravitational force is zero ? if you think so , please answer where that point might be , closer to earth or closer to the moon ?
Physics Gravitation Level: High School
Why are the planets , the sun , the moon, all spherical shapes ?