Question

An object is moving with a velocity of 20m/s a force of 10N is acting perpendicular what will be the speed after 10 seconds

Answer 1

force acting perpendicular to velocity .
let object moves in x -direction with 20m/s velocity and force acting on it y-direction then,
use kinematics equation in vector form,
v^ = u^ + a^t
here you didn't mention about mass of body .
let mass of body = m
then acceleration = F/m
= 10/m m/s²

v^ = 20 i + 10/m × 10 j
= 20 i + 100/m j