# In an inertial frame of reference, a force of 100 N imparts an acceleration of 10 m / s ^ 2

**In an inertial frame of reference, a force of 100 N imparts an acceleration of 10 m / s ^ 2 to a certain body. What force will impart an acceleration of 7 m / s ^ 2 to this body?**

F1 = 100 N.

a1 = 10 m / s2.

a2 = 7 m / s2.

F2 -?

In the inertial reference frame, Newton’s 2 law is true. According to 2 Newton’s law, to find the mass of a body m, the force F that acts on it must be divided by its acceleration a: m = F1 / a1.

Since the mass of the body does not change, according to Newton’s 2 law, the force F2, which acts on the body, is equal to the product of the body’s mass m by its acceleration a2: F2 = m * a2.

F2 = F1 * a2 / a1.

F2 = 100 N * 7 m / s2 / 10 m / s2 = 70 N.

Answer: the body is imparted by the acceleration a2 = 7 m / s2 by the force F2 = 70 N.