Blocks, Friction Forces and Acceleration

AI Thread Summary
A block weighing 50.0 N is subjected to a horizontal force of 25.0 N, with static and kinetic friction coefficients of 0.510 and 0.350, respectively. The static friction force is calculated to be 25.5 N, which exceeds the applied force, indicating the block will move. Once in motion, the kinetic friction force is determined to be 17.5 N. To find the block's acceleration, the net force is calculated by subtracting the kinetic friction from the applied force. The discussion emphasizes using Newton's second law to analyze the forces acting on the block.
sunnyorange
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I am having trouble with this problem:
A block whose weight is 50.0N rests on a horizontal table. A horizontal force of 25.0 N is applied to the block. The coefficients of static and kidnetic friction are 0.510 and 0.350 respectively. Will the Block move under the influence of the force and if so, what will be the block's acceleration?
What I have so far:
1. Fs=mu sN
=0.510*50
=25.5 N
25.5 N>25.0 N, therefore the block will move under the influence of the force.
2. Finding acceleration
I know I have to find the net force then use that in the second law equation. How do I do that.
I have kinetic force=17.5, mass=50/9.8=5.10 kg.
Please help!:cry:
 
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sunnyorange said:
25.5 N>25.0 N, therefore the block will move under the influence of the force

You might want to look at this again. Which one was the force due to static friction?
 
You are correct so far.

Think Newton's second law: the pulling force stays the same, but now instead of static friction, there is kinetic friction. What's the net force?
 
Would the net force be: applied horizontal force-kinetic friction force?
 
yes, that's correct (there are two other forces in the vertical direction, but Normal force and weight will balance each other in *this* situation).
 
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