Question

I would like to know why this is the correct answer

-A spring scale shows a net force of 0.8 N acting on a 1.5-kg mass. What happens to the acceleration of the object if the net force is decreased to 0.2 N?

*The acceleration decreases to a quarter of its original value, or about 0.13 m/s2.

Answer 1

The acceleration of the object if the net force is decreased = 0.13 m/s²

Further explanation

Given

A net force of 0.8 N acting on a 1.5-kg mass.

The net force is decreased to 0.2 N

Required

The acceleration of the object if the net force is decreased

Solution

Newton's 2nd law :

$\tt \sum F=m.a$

The mass used in state 1 and 2 remains the same, at 1.5 kg

• state 1

ΣF=0.8 N

m=1.5 kg

The acceleration, a:

$\tt a=\dfrac{\sum F}{m}\\\\a=\dfrac{0.8}{1.5}\\\\a=0.53`m/s^2$

• state 2

ΣF=0.2 N

m=1.5 kg

The acceleration, a:

$\tt a=\dfrac{\sum F}{m}\\\\a=\dfrac{0.2}{1.5}\\\\a=0.13~m/s^2$