Question

A stone of mass m is thrown from earths surface at an angle to the horizontal with an initial velocity ignoring the air drag, the power developed by gravity force t second after the beginning of motion is :

Answer 1

Explanation:

Kinetic Energy

For an object with mass m and speed v, the kinetic energy is defined as

K =

1

2mv2

(6.1)

Kinetic energy is a scalar (it has magnitude but no direction); it is always a positive

number; and it has SI units of kg · m2/ s

2

. This new combination of the basic SI units is

known as the joule:

1 joule = 1 J = 1 kg·m2

s

2 (6.2)

As we will see, the joule is also the unit of work W and potential energy U. Other energy

units often seen are:

1 erg = 1 g·cm2

s

2 = 10−7

J 1 eV = 1.60 × 10−19 J