Aball rolls down the hill which has a vertical height of 15 m. ignoring friction what would be the gravitational potential energy of the ball when it is at the top of the hill? what would be the velocity of the ball when it reaches the bottom of the hill?

a) Potential energy: 147 m [J]

The gravitational potential energy of an object is given by

where

m is its mass

is the acceleration of gravity

h is the height of the object above the ground

In this problem,

h = 15 m

We call 'm' the mass of the ball, since we don't know it

So, the potential energy of the ball at the top of the hill is

(J)

b) Velocity of the ball at the bottom of the hill: 17.1 m/s

According to the law of conservation of energy, in absence of friction all the potential energy of the ball is converted into kinetic energy as the ball reaches the bottom of the hill. Therefore we can write:

where

v is the final velocity of the ball

We know from part a) that

U = 147 m

Substituting into the equation above,

And re-arranging for v, we find the velocity:

with 5 seconds, no, but over time if the police car stays at 65m/s ad the speeding car stays at 60, then obviously yes, but the answer to your question would be, no.

hope this : )

explanation:

earth's surface is mainly heated by the absorption of infrared radiation from the sun.

evaporation occurs because molecules in liquid water are warmed ( usually by the sun) and vibrate quicker, becoming less dense and rise.

condensation occurs because molecules in water vapor are cooled and therefore vibrate more slowly thus becoming more dense and eventually fall to earth.

lines of equal barometric pressure on a weather map are called: isobars : lines of equal temp on a weather map are called: isotherms.​