# Wow is there no one to help with physics???

posted by on .

A crate of oranges weighing 209 N rests on a flatbed truck 2.0 m from the back of the truck. The coefficients of friction between the crate and the bed are μs = 0.41 and μk = 0.20. The truck drives on a straight, level highway at a constant 7.5 m/s.

(a) What is the force of friction acting on the crate?
N

(b) If the truck speeds up with an acceleration of 2.1 m/s2, what is the force of the friction on the crate?
magnitude N

(c) What is the maximum acceleration the truck can have without the crate starting to slide?
m/s2

• Wow is there no one to help with physics??? - ,

Please have patience, John. You just posted about 11 minutes before this post.

Remember that we are all volunteers and answer questions when we have spare time.

Here's a clue: A busy physics teacher is more likely to help you if you give us some idea what you do and don't understand about the problem.

• Wow is there no one to help with physics??? - ,

Sorry

Well i am confused i don't know how to set the problem up to solve for! I don't know whether to use both uK and Us or just one of them :/

Thank you

• Wow is there no one to help with physics??? - ,

John -- or whatever you call yourself -- please keep the same name for all of your posts.

• Wow is there no one to help with physics??? - ,

How would you know its all me?

• Wow is there no one to help with physics??? - ,

mustatic use when at rest.

• Wow is there no one to help with physics??? - ,

Thanks bobpursley

• Wow is there no one to help with physics??? - ,

I got the rest bobpursley but for some reason am not getting the right answer for part b which friction=ma but when i put 209(2.1) the answer isnt right