# physics

posted by on .

A wood block, after being given a starting push, slides down a wood ramp at a constant speed. What is the angle of the ramp above horizontal?
The fact that there aren't any numbers involved here and a certain angle is required confuses me. I know it involves Newton's second law but don't we at least need to know weight of the block?

• physics - ,

You don't need to know the mass of the block, but you DO need to know the kinetic coefficient of friction, Uk.

They should have provided a numerical value for Uk, unless they want the angle expressed in terms of Uk

The angle of the ramp is tan^-1(Uk)

The coefficient of friction for wood sliding on wood depends upon the smoothness and wetness of the surfaces. You can't just "look it up"

• physics - ,

thank you for helping but this is exactly my problem. That is all the information given and we have to fill in a value and units blank. When i have countlessly tried to put in tangent in any way possible, a message pops up: "Use either an integer, decimal number, or scientific notation for the numeric portion of your answer. Do not use calculations or functions." I'm at my wits end with this problem

• physics - ,

The problem is not with you, it is with the course you are taking. Whoever is responsible for the question or the course content should not be teaching.

You cannot come up with numbers to physics questions without numerical inputs

• physics - ,

It's the homework system--it's all online. I can figure out the questions with numbers but this one has me stumped. Thanks anyways, maybe there's a glitch in the system or something...

• physics - ,

kir