Question

Certain force acting on a 20 kg mass changes its velocity from

5m/s to 2 m/s. Calculate the work done by the force​

Answer 1

Explanation:

$\huge\fcolorbox{blue}{green}{Given}$

• Mass = 20kg.

• Change in Velocity = 5m/s to 2 m/s.

$\huge\fcolorbox{blue}{green}{Formulas used}$

Kinetic energy is given by the expression

• (E k) v = 1/2 mv^2

$\huge\fcolorbox{blue}{green}{Solution}$

➣ E k= Kinetic energy of the object moving with a velocity, v

➣ Kinetic energy when the object was moving with a velocity 5 m s-1

➣ (E k)5 = 1/2 — 20 — (5)2 = 250 J

➣ Kinetic energy when the object was moving with a velocity 2 m s-1

➣ (E k)2 = (1 )/2x 20 — (2)2 = 40 J

➣ 40 J

Answer 2

Mass = 20kg.

Change in Velocity = 5m/s to 2 m/s.

Formulas used:

Kinetic energy is given by the expression

(E k) v = 1/2 mv^2

E k= Kinetic energy of the object moving with a velocity, v

Kinetic energy when the object was moving with a velocity 5 m s-1

(E k)5 = 1/2 — 20 — (5)2 = 250 J

Kinetic energy when the object was moving with a velocity 2 m s-1

(E k)2 = (1 )/2x 20 — (2)2 = 40 J

40 J

hope it helps ........... ❣️