Mechanics

Running a finger around the rim of a glass will "stimulate" the glass. We are adding energy to the glass, and because the finger tends to "slip and grab" as it moves around the rim, the energy is delivered in "pulses" to the glass. This tends to make the glass vibrate, and we are adding to the vibrational energy by continuously running our finger around the rim of the glass. The net result is that the glass will "sing" to us in a given pitch.

Some glasses lend themselves better to this experiment than others, and most stemware works quite well, even "cheaper" types. When doing an experiment, moistening the finger will help things. This is a good project to investigate some things in basic physics, though the principles at work may be a bit less than clear. The glass, like other objects, has a natural resonance, and we "tap into" that by mechanically stimulating the glass at the rim with our finger. When we find the glass beginning to vibrate, we can move our finger a bit faster or slower to add energy "in sync" with the vibrations, thus sustaining and increasing them.

Alternately, as we step: sliding, or dynamic friction; static friction; sliding friction again. Sequence repeats with each step.

answer is (D) 120N

2181 N/m

Sound waves are longitudinal in nature, and they require a medium for propagation.

Generally, north, east, right, and forward are considered positive directions. South, west, left, and backward are considered negative directions. So if a body is moving south, west, left, or backward, its velocity is considered to be negative.

Yes, some work is converted into heat due to the friction.

sliding friction

You are'nt destroying energy when u wasted it. It is converted into another form of energy. ie.( when you are driving a car, the car's kinetic energy is wasted because it is reduced by the friction encountered, however the reduced kinetic energy is converted into heat energy) Hence, Energy can neither be destroyed nor created.

Liquid rises and falls when heated because when heated, liquid will expand causing it to be less dense than the other liquid around it. This results in a buoyant force and it will rise.

After rising it will start to cool off since it isn't by the heat source anymore and will become more dense. This will make it more dense than the newly heated up liquid below it and so it will fall to repeat the process.

Well since it is buoyant, it rises until it cools enough to begin falling again.

glass

Nothing.

Actually gravity is pushing you down but there is enough air resistance on the earth to stop us feeling heavy and crushed

Accelerate at a constant rate (although if the net force is zero, this constant acceleration would be zero, so it wouldn't really be proper to say its accelerating in that case).

Yes, it does.

Acceleration is a change in velocity per unit of time.

Front axle shaft nut torque: 175 ft lbs. Rear axle hub nut torque: # Tighten the adjustment nut to 163-190 N·m (120-140 ft. lbs.) while rotating the wheel. # Loosen the adjustment nut 1/8 of-a-turn (120 degrees) to provide 0.001-inch to 0.010-inch wheel bearing end play.

If the net force on a body is zero, then the body will not accelerate ... its speed and direction of motion won't change. If it was moving a second ago, then it will continue moving at the same speed and in the same direction. If it was not moving a second ago, it won't start moving.

Since force is a function of acceleration and an object at rest has zero acceleration, then then net force is zero as well.

Increase the number of wheels and/or increase the tread width of the tires or tracks, so that their weight is distributed over a larger area.

Screws are more effective than nails by gripping a portion of the material they are driven into. a screw can sustain a lot more force before being pulled out than a standard nail can.

In a perfectly inelastic collision, the two objects stick together and the momentum is conserved. Once the objects stick together, they both have the same velocity.

p = mv

where p is the momentum

conservation of momentum for perfectly inelastic collision:

m1v1i + m2v2i = (m1 + m2)vf

(1kg)(6m/s) + (3kg)(0m/s) = (1 kg + 3kg)vf

6 kg·m/s = (4kg) vf

vf = v1f = v2f = 1.5 m/s

this is false. the horizontal speed of the object has absolutely nothing to do with how long it takes to fall. if you fire a bullet on level ground it will hit the ground at the same time an apple would if you drop it from the same distance above the ground at the same time. the force of gravity is the same on everything on earth.

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