## How to Calculate and Solve for Reaction: Lift Moves Down | Motion The image above represents reaction: lift moves down.

To compute for reaction: lift moves down, three essential parameters are needed and these parameters are mass (m), acceleration (a) and acceleration due to gravity (g).

The formula for calculating reaction: lift moves down:

R = m(g – a)

Where;

R = Reaction
m = Mass
g = acceleration due to gravity
a = Acceleration

Let’s solve an example;
Find the reaction when the mass is 28, acceleration is 9 and acceleration due to gravity is 9.8.

This implies that;

m = Mass = 28
g = acceleration due to gravity = 9.8
a = Acceleration = 9

R = m(g – a)
R = 28(9.8 – 9)
R = 28(0.80)
R = 22.4

Therefore, the reaction is 22.4 N.

Calculating the Mass when the Reaction, the Acceleration and the Acceleration due to Gravity is Given.

m = R / g – a

Where;

m = Mass
R = Reaction
g = acceleration due to gravity
a = Acceleration

Let’s solve an example;
Find the mass when the reaction is 42, the acceleration is 8 and the acceleration due to gravity is 9.8

This implies that;

R = Reaction = 42
g = acceleration due to gravity = 9.8
a = Acceleration = 8

m = R / g – a
m = 42 / 9.8 + 8
m = 42 / 17.8
m = 2.359

Therefore, the mass is 2.359.