Remove a force, what would be the resultant

[ammoun]

Homework Statement

A packing crate rests on a horizontal surface. It is acted on by three horizontal forces: 1000N to the left, 300N to the right, and friction. The weight of the crate is 500N. If the 1000N force is removed, the resultant force acting on the block is

A) zero
B) 300 N to the left
C) 300 N to the right
D) 500 N to the left
E) impossible to determine from the information given.

The Attempt at a Solution

I would say E) since I have no info about the friction. Could you please confirm.

Thank you

 

[davo789]

It's not brilliantly worded, but I think the clue is when it says that the 'crate *rests* on a horizontal surface'. i.e. it isn't moving. That should give you some info about the friction force.

 

[ammoun]

Alright so when the crate is resting the friction would be 700.

If we remove the 1000 N force, the friction would be to the opposite direction and decrease to 300 to cancel the right force.

The resultant force would A) zero.

Is there any problem in this reasoning.

 

[davo789]

Looks fine to me!

 

[rwisz]

for your response. Yes, E) is the correct answer. Without information about the friction force, it is impossible to determine the resultant force acting on the crate after removing the 1000N force. The friction force could potentially counteract the 300N force and result in a resultant force of zero, or it could add to the 300N force and result in a resultant force of 300N to the left or right. Without knowing the magnitude and direction of the friction force, we cannot determine the resultant force.