- #1
Eclair_de_XII
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Homework Statement
"A block is projected up a frictionless inclined plane with initial speed v0 = 3.50 m/s. The angle of incline is θ = 32.0°. (a) How far up the plane does the block go? (b) How long does it take to get there? (c) What is its speed when it gets back to the bottom?"
Homework Equations
Fg = mg⋅sinθ
Fx = -Fg
Assume: arbitrary mass of block is 1-kg
The Attempt at a Solution
(b) Fg = (1kg)(9.8m/s2)(sin (-32°)) = -5.1932N
5.1932N = (1kg)(3.5m/s)/t
t = (3.5 kg⋅m/s)/5.1932N = 0.674 s
I've only figured out how to find the time it takes for the block to reach that point on the slope before it slips back down. The book says its speed when it gets back to the bottom is 3.50 m/s; same as the initial velocity. I have a vague idea how to solve for how far the block goes. Basically, I figure that once v0 = 0, it has reached the maximum point it can reach at the initial velocity at 3.50 m/s before it comes down due to gravity, anyway. At that point, gravitational force and the force pushing the box should be equal. But I have no idea how I would apply this.