Aball with a mass of 0.5 kilograms is lifted to a height of 2.0 meters and dropped. it bounces back to a height of 1.8 meters.
the energy of the ball has been reduced by (0.98, 8.82, 9.8) joules after bouncing back. this reduction happens because potential energy transforms to (kinetic, light, thermal energy).

hint: use pe = m × g × h where g = 9.8 m/s2.

Change in potential energy,

Explanation:

It is given that,

Mass of the ball, m = 0.5 kg

It is lifted to a height of, Initial height, h = 2 m

It bounces back to a height of 1.8 meters, final height, h' = 1.8 m

It can be assumed to find the change in potential energy in the entire process. Let is the initial potential energy. It is given by :

Let is the final potential energy. It is given by :

Let is the change in potential energy. It is equal to :

So, the change in gravitational potential energy is 0.98 J. Hence, this is the required solution.

5 w for 1hr = 5x60x60 joules=300x60=3000x6=18,000j as total energy conversion. efficiency of bulb needed for radiant to thermal within 18000

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.