How Far Does a Block Slide Up an Incline with Friction?

[TWPC920]

Homework Statement

A 4 kg block is given an initial velocity of 5 m/s upward along a 30 degree incline. If the coefficient of sliding friction between the block and the surface of the incline is .42, find the upward displacement of the block along the incline, between the point of its initial velocity and the point at which it comes momentarily to rest

Homework Equations

Fg = ma
Ffr = coefficient x Fg x cos theta
V squared = V0 Squared + 2A(X-X0)

The Attempt at a Solution

Set it so Fg = 9.8 x 4
Plug into Ffr equation
Ffr = .42 x 39.2 x cos 30
Ffr = 14.26
Need help from here on

 

[tiny-tim]

Welcome to PF!

Hi TWPC920! Welcome to PF!

Homework Statement

A 4 kg block is given an initial velocity of 5 m/s upward along a 30 degree incline. If the coefficient of sliding friction between the block and the surface of the incline is .42, find the upward displacement of the block along the incline, between the point of its initial velocity and the point at which it comes momentarily to rest
…
Set it so Fg = 9.8 x 4
Plug into Ffr equation
Ffr = .42 x 39.2 x cos 30
Ffr = 14.26
Need help from here on

ok, you've got the friction force, now use good ol' Newton's second law in the direction of the slope …

F_slope = ma_slope, where F_slope is the sum of the friction force and the slope component of the gravitational force.

Then use that value of a_slope in the constant acceleration equation you mentioned.