Question

A body of mass 10 kg at rest is acted upon simultaneously by two forces 4 N and 3 N at right angles to each other. The kinetic energy of the body at the end of 10 s is

Options

• 50 J

• 100 J

• 125 J

• 300 J

Answer 1

125 J

Explanation:

Net force on body = `sqrt(4^2 + 3^2)` = 5 N

∴ a = F/m = 5/10 = `1/2` m/s²

Kinetic energy = `1/2` mv² = `1/2` m(at)²

= `1/2 xx 10 xx (1/2 xx 10)^2`

= 125 J