Carpet asorbs sound, so glass should make it echo.
The old style (incandescent) light bulb converts more energy
into heat than it does into light. If you're using it mainly as a
source of light, then it's a bummer, and its efficiency is very low.
BUT ... if you're using an incandescent light bulb as a heater, then
its efficiency is much better. It all depends on your point of view.
All of Dina's potential energy Ep is converted into kinetic energy Ek so Ep=Ek, where Ep=m*g*h and Ek=(1/2)*m*v². m is the mass of Dina, h is the height of ski slope, g=9.8 m/s² and v is the maximal velocity.
So we solve for v:
m*g*h=(1/2)*m*v², masses cancel out,
g*h=(1/2)*v², we multiply by 2,
2*g*h=v² and take the square root to get v
√(2*g*h)=v, we plug in the numbers and get:
v=9.9 m/s.
So Dina's maximum velocity on the bottom of the ski slope is v=9.9 m/s.
Bodies in space traveled in circles.
The planets revolved around the Earth.
If the length and linear density are constant, the frequency is directly proportional to the square root of the tension.
