ToughSTEM
Sign Up
Log In
ToughSTEM
A question answer community on a mission
to share Solutions for all STEM major Problems.
Cant find a problem on ToughSTEM?
1
You and your friend Peter are putting new shingles on a roof pitched at 24 degrees . You're sitting on the very top of the roof when Peter, who is at the edge of the roof directly below you, 5.0m away, asks you for the box of nails. Rather than carry the 2.1kg box of nails down to Peter, you decide to give the box a push and have it slide down to him.

A) If the coefficient of kinetic friction between the box and the roof is 0.53, with what speed should you push the box to have it gently come to rest right at the edge of the roof?
Edit
Added Mon, 22 Jun '15
Community
1
Comment
Add a Comment
Solutions
1
The frictional force is given by µN where N = mgcos theta

The force equation F = ma

is: mgsin theta - µmgcos theta = ma

m cancels so,

a = g(sin theta - µcos theta)

where ? = 20 deg, µ = 0.53 and g = 9.81 m/s^2

Next we use the equation v^2 = u^2 + 2as

v = 0, s = 5.0 m

Thus

u^2 = - 2sg(sin? - µcos?)
        = -2*9.81*5.0 (sin20 - 0.53cos20)

u = 5.72 m/s
Edit
Added Mon, 22 Jun '15
Community
1
Comment
Add a Comment
Add Your Solution!
Close

Click here to
Choose An Image
or
Get image from URL
GO
Close
Back
Add Image
Close
What URL would you like to link?
GO
α
β
γ
δ
ϵ
ε
η
ϑ
λ
μ
π
ρ
σ
τ
φ
ψ
ω
Γ
Δ
Θ
Λ
Π
Σ
Φ
Ω
Copied to Clipboard

Add Your Solution
Sign Up
to interact with the community. (That's part of how we ensure only good content gets on ToughSTEM)
OR
OR
ToughSTEM is completely free, and its staying that way. Students pay way too much already.
Almost done!
Please check your email to finish creating your account!
Welcome to the Club!
Choose a new Display Name
Only letters, numbers, spaces, dashes, and underscores, are allowed. Can not be blank.
Great! You're all set, .
A question answer community on a mission
to share Solutions for all STEM major Problems.
Why
The Purpose
How
The Community
Give Feedback
Tell us suggestions, ideas, and any bugs you find. Help make ToughSTEM even better.