Question

on an object of mass 1 kg moving along X-axis with constant speed 8m/s a constant force 2 N is applied in positive y direction. find its speed after 4 seconds

Answer 1

Velocity along y-axis after 4 s is
v_y = u + at
= (0 m/s) + [(2 N / 1 kg) × 4 s]
= 8 m/s

Velocity along x-axis after 4 seconds is still 8 m/s
v_x = 8 m/s

∴ Velocity of body after 4 seconds is (8i + 8j) m/s

Speed after 4 seconds is
|v| = √[(8 m/s)² + (8 m/s)²] = 8√2 m/s