Question

Exercise 2: A 0.6 kg particle has a speed of 2 m / s at point A and kinetic energy of 7.5 J at point B. What is

Answer 1

Explanation:

We have,

Mass of a particle is 0.6 kg

Speed at A is 2 m/s

Kinetic energy at B is 7.5 J

(a) The kinetic energy at A is given by :

$K_A=\dfrac{1}{2}mv^2\\\\K_A=\dfrac{1}{2}\times 0.6\times 2^2\\\\K_A=1.2\ J$

(b) Kinetic energy at B is given by

$K_B=\dfrac{1}{2}mV^2\\\\V=\sqrt{\dfrac{2K_B}{m}} \\\\V=\sqrt{\dfrac{2\times 7.5}{0.6}} \\\\V=5\ m/s$

(c) The work done on the particle as it moves form A to B is given by work energy theorem as :

$W=\dfrac{1}{2}m(V^2-v^2)\\\\W=\dfrac{1}{2}\times 0.6\times (5^2-2^2)\\\\W=6.3\ J$