Question

According to Newton's first law of motion, no force is needed to keep a body in motion with
a. zero
b. constant
c. maximum
d. positive ​

Answer 1

answer:

Correct option is

D

explanation:To keep the body in uniform velocity

According to law of inertia or Newton's first law of motion, a body in state of rest or of uniform motion remains in state of rest or of uniform motion unless it is acted upon by an external force. Hence a body in uniform motion required no force to keep them in uniform motion.

Given that force = mass x acceleration

Constant speed means there is no acceleration, therefore if acceleration = 0 force is also 0.

So a force is not necessary to maintain speed, assuming no friction.