Number of results: 110,947
HI well i have two questions 1) a 2.0-m-long pendulum is released from rest when the support string is at an angle of 25 with the vertical. what is the speed of the bob at the bottom of the swing? 2)A 2.0*10^3-kg car starts from rest at the top of a 5.0-m-driveway that is ...
Monday, November 27, 2006 at 8:57pm by becky
when you apply the brakes of a car its kinetic energy or energy of motion decreases. a)to what form of energy is the kinetic energy converted? b)where does the resulting energy end up? Do the brake drums on the wheels heat up? so does it convert into heat energy?and the ...
Tuesday, May 8, 2007 at 4:32am by Emma
some people refer to heat as "low grade energy. a)how is low grade energy different from high grade energy? b)give two example of high grade energy When heating a cup of tea, which would be preferable...a stove with a burner on top, or a heating pad? High grade energy is ...
Tuesday, May 8, 2007 at 4:41am by Emma
a mordern power station,or, more correctly, an energy station, converts heat energy into electrical energy at an efficiency od 50% if the station produces electrical energy at a rate of 1.00GW from burning coal, calculate the mass of coal it burns each day. the coal it uses ...
Wednesday, May 9, 2007 at 6:57am by Emma
Physics Work and Energy, Momentum
Let g be the acceleration due to gravity at the surface of a planet of radius R. Which of the following is a dimensionally correct formula for the minimum kinetic energy K that a projectile of mass m must have at the planet's surface if the projectile is to escape from the ...
Sunday, May 13, 2007 at 4:35pm by Kelly
Please help... Let g be the acceleration due to gravity at the surface of a planet of radius R. Which of the following is a dimensionally correct formula for the minimum kinetic energy K that a projectile of mass m must have at the planet's surface if the projectile is to ...
Sunday, May 13, 2007 at 6:37pm by Kelly
Q) Rows of wind-powered generators are used in various windy locations to generate electric power. Does the power generated affect the windmills be windier if they weren't there? Dicuss in terms of energy conservation.
Sunday, November 18, 2007 at 12:38am by Sam
Q) Rows of wind-powered generators are used in various windy locations to generate electric power. Does the power generated affect the speed of the wind?Would Locations behind the windmills be windier if they weren't there? Dicuss in terms of energy conservation.
Sunday, November 18, 2007 at 4:48am by Sam
If they collide elastically the sum of 1/2 m v^2 after has to equal the sum of 1/2 m v^2 s before and the momentums (m1v1+m2v2) must be the same before and after. This can only happen if the first one stops and the second one proceeds at 6 m/s. I will leave you to prove that ...
Thursday, January 17, 2008 at 10:07pm by Damon
Physics - drwls can you help me with this?
Using the energy conservation is always a good shortcut to get conditions at turnaround points, or maximum velocities, when there is oscillatory motion. You would used Newton's law of acceleration if you wanted to solve for the equation of motion vs. time. The quickest way to ...
Wednesday, February 20, 2008 at 1:16am by drwls
The woman's name was Fay Wray, not Fay Wrap. Perhaps your teacher is trying to be funny. He or she should be more careful explaining the important forces on the shoe. The answer that you get with the energy-conservation equation suggested (which neglects air resistance) will ...
Wednesday, September 24, 2008 at 9:21pm by drwls
This IS a kinematics problem. Any equation used to solve it involves kinematics. An exact solution would require solving a (kinematic) differential equation. A good approximation to part (a) can be obtained by assuming an average air resistance force of |V|/60 , where V is the...
Saturday, November 8, 2008 at 10:50pm by drwls
I suggest you try an energy conservation approach. The work done against friction will equal the initial system total energy. From that you can deduce the friction force and coefficient. The kinetic energy when contact with the spring is lost equals the initial stored spring ...
Sunday, November 16, 2008 at 8:26pm by drwls
Theta is the maximum amplitude of the swinging motion, but they want the tension when the rope is vertical. The tension at that time will equal the sum of the weight (mg) and the centripetal force required by the velocity and length (mV^2/L) V will depend upon the amplitude of...
Sunday, November 23, 2008 at 10:00am by drwls
(a) They tell you that is is an elastic collision. Let's call the velocities V1i = vi = speed of initially moving proton V2i = 0 (initially at rest proton) Vif (final speed of initially moving proton) V2f = (final speed of initially moving proton) They tell you that V2f/V2f = ...
Thursday, November 27, 2008 at 1:43pm by drwls
The speed of the sliding cube at impact is V = sqrt(2gH) = 2.42 m/s Next you have to figure out the velocities of the sliding cube (mass M) and the impacted cube (Mass M/2), after impact. You need to write equations of both momentum and kinetic energy conservation. You will ...
Sunday, December 7, 2008 at 1:22am by drwls
what are the forces acting on a string that is wounded around a uniform disk of Radius R and mass R? i know tension is in the string...what else? and I of the disk is 1/2 MR2... so how would you show that the tension in the string is one third the weight of the disk? and......
Monday, December 15, 2008 at 10:51pm by Stacu
There is also a shortcut way to do this using "energy conservation" that will give the same answer. At the maximum height H, the potential energy increase M g H will equal the initial kinetic energy, (1/2) M Vo^2) Therefore H = Vo^2/(2g)
Saturday, February 7, 2009 at 1:57pm by drwls
Suppose the diver vaults off the springboard, leaving it with an initial speed of 3.27 m/s upwards. Use energy conservation to find his speed when he strikes the water.
Thursday, March 19, 2009 at 6:12pm by cbrown
I'm confused and am hoping someone could help me understand energy can neither be created nor destroyed... great... so in physics classes we can set up problems and stuff were KEo + PEo = KE + PE Energy intial equals energy final sense energy is conserved but then when ...
Monday, October 19, 2009 at 8:29pm by Physics