A constant force acting on a body of mass 3.0 kg changes its speed fro

1.	A constant force acting on a body of mass 3.0 kg changes its speed from 2.0 m/s to 3.5 m/s in 25 s. The direction of the motion of the body remains unchanged. What is the magnitude and direction of the force?
Answer» Given m = 3 kg u = 2 m/s v = 3.5 m/s t = 25 s. F = ma but we know that a = \(\frac {v-u}{t}\) ∴ F = m \(\frac {(v-u)}{t}\) = 3 \((\frac {3.5-2}{25})\) = 0.18 N since direction acceleration ‘a’ is positive force is acting in the direction of motion.

A constant force acting on a body of mass 3.0 kg changes its speed from 2.0 m/s to 3.5 m/s in 25 s. The direction of the motion of the body remains unchanged. What is the magnitude and direction of the force?

Answer»

Given m = 3 kg

u = 2 m/s

v = 3.5 m/s

t = 25 s.

F = ma

but we know that a = \(\frac {v-u}{t}\)

∴ F = m \(\frac {(v-u)}{t}\) = 3 \((\frac {3.5-2}{25})\)

= 0.18 N

since direction acceleration ‘a’ is positive force is acting in the direction of motion.