When AC is switched on the thin metallic disc is found to thrown up in air.
What makes the disc to be thrown?

Take a strong cyclindrial electromagnet connected to AC source and place a light metalic disc at the top is it. When the current is switched on , the disc is throw up in the air. Why does the disc go up?

There is a hole in metal disc.What happens to the size of the metal disc if the metal disc is heated?

A stone is thrown up with a velocity u' whiwhich makes an angle theta with the horizontal.

Lifting a small stone to a certain height and then dropping it downwards. What change takes place in the speed of the stone as it is thrown up?