Calculate Normal Force: Crate & Person on Floor

[Pizza Dave]

Please help with below. is it correct?

A 41 kg crate rests on a horizontal floor and a 67kg person is standing on the crate.

a. determine the magnitude of the normal force the floor exerts on the crate

b. determine the magnitude of the normal force that the crate exerts on the person

Homework Equations

(m1+m2)G
M2(G) [/B]

The Attempt at a Solution

a. 1080
b. 670 [/B]

 

[AlephNumbers]

Try drawing a force diagram for both the person on the crate and the crate and try summing your forces for each individually. The answers should become clear!Also, this belongs in introductory physics.

 

[carl_loves_math]

AlephNumbers, this was an impertinent response.

Pizza Dave, you calculated this answer correctly, but it looks like you substituted 10 for the force of gravity instead of the actual value of 9.8. This may help your answers be more accurate in the future!

 

[haruspex]

a. 1080
b. 670

You should always specify units (unless instructed otherwise).

it looks like you substituted 10 for the force of gravity instead of the actual value of 9.8.

Both values are just approximations. Often students are told to use 10 ms^-2. On the other hand, if it is approximated to 10 then, logically, the answers should only be given to the same precision, e.g. 1100 N for (a).
And you mean gravitational acceleration, not force.