The maximum force that the handles on a grocery bag....

Question

The maximum force that the handles on a grocery bag can withstand and not rip is 250 N.
a. If 20 kg of groceries are lifted from the floor to the table with an acceleration of 5 m/s2, will the bag hold? (ans. No - as proven)

b. If the bag was lowered with the same acceleration would it be able to hold more or less mass? Prove with equations.

Answer 1

a)

 

Calculate the force.  You are given the mass and acceleration.  Multiply them.

 

F = 20 kg * 5 m/s²

F = 100 N

 

Now we compare this force to the maximum force.  This force is less than the maximum force.  Therefore, the bag will hold.  You answer should not be "No-as proven".

 

 

b)

 

Find the mass when the force is at its maximum.  This is because when the force is increased, so is the weight.  Lowering the bag indicates that the weight has increased.

 

m = F / a

 

m = 250 / 5

 

m = 50 kg

 

 

When the force is increased from 100 N to 250 N, the mass increases from 20 kg to 50 kg.  The bag is able to hold more mass, but 50 kg is the maximum it can get.