# Homework Help: Physics! force exerted

1. Oct 15, 2008

### Claudia16

1. The problem statement, all variables and given/known data
a 5.9 kg bucket of water is raised from a well by a rope.
the acceleration of gravity is 9.81 m/s^2
if the upward acceleration of the bucket is 4.0 ,\m/s^2, find the force exerted by the rope on the bucket of water. in units of N

2. Relevant equations

3. The attempt at a solution

ok i know that i have two forces.
1. The weight of the bucket which is downward:
2. The force by the rope which should be upward in orderto overcome the weight and gives the bucket an upward acceleation

2. Oct 15, 2008

### PhanthomJay

Welcome to PF!
yes
yes
yes, the upward force must be greater than the weight to produce a net upward force giving an upward acceleration. What does newton 2 say about net forces?

3. Oct 15, 2008

### Claudia16

A particle will stay at rest or continue at a constant velocity unless acted upon by an external unbalanced net force

4. Oct 15, 2008

### Claudia16

F = ma: the net force on an object is equal to the mass of the object multiplied by its acceleration

5. Oct 15, 2008

### PhanthomJay

OK. So find the net unbalanced force in terms of the unknown rope force (call it T) and the bucket's weight. Then set it equal to m*a to solve for T.

6. Oct 15, 2008

### Claudia16

ok so the mass of the bucket (m) times the acceleration of the bucket (a) will give me T= the force exerted by the rope??

7. Oct 15, 2008

### hsywci

set one direction as positive (either up or down)