How much tension should the rope be able to withstand?

In summary, the tension in the rope must be greater than the weight of the car in order to have a net force that is up.
  • #1
Ryuk1990
158
0

Homework Statement



A rope is pulling up a 1200 Kg car. The upwards acceleration is 0.8 m/s2. How much tension should the rope be able to withstand?

Homework Equations



Net force is equal to mass x acceleration.

The Attempt at a Solution



So would it just be 1200 Kg x 0.8 m/s2 which is 960 Newtons?
 
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  • #2
Ryuk1990 said:

Homework Statement



A rope is pulling up a 1200 Kg car. The upwards acceleration is 0.8 m/s2. How much tension should the rope be able to withstand?

Homework Equations



Net force is equal to mass x acceleration.

The Attempt at a Solution



So would it just be 1200 Kg x 0.8 m/s2 which is 960 Newtons?
That's the net force. The net force is the algebraic sum of all the forces acting on the car. What are the forces acting on the car?
 
  • #3
PhanthomJay said:
That's the net force. The net force is the algebraic sum of all the forces acting on the car. What are the forces acting on the car?

The normal force and gravity?
 
  • #4
Ryuk1990 said:
The normal force and gravity?
Gravity is one force acting down on the car (it's weight). The other force is the contact force (which perhaps you are calling the normal force) which is actually the ___?____ force in the ____?___ which acts ______________(up/down, choose one).
 
  • #5
The net force in the system which acts up?
 
  • #6
Ryuk1990 said:
The net force in the system which acts up?
You have already calculated the net (resultant) force. It is equal to 960 N. The net force always acts in the direction of the acceleration, thus, the net force of 960 N acts up. The net force on the car is comprised of 2 forces: the weight of the car, acting down, and the rope tension, which must act up (since the net force is up, the tension force must be greater than the weight force). So you have the tension force acting up, and the weight force acting down, and their net total (algebraic sum) must be 960N .. So the tension force is ?
 
  • #7
PhanthomJay said:
You have already calculated the net (resultant) force. It is equal to 960 N. The net force always acts in the direction of the acceleration, thus, the net force of 960 N acts up. The net force on the car is comprised of 2 forces: the weight of the car, acting down, and the rope tension, which must act up (since the net force is up, the tension force must be greater than the weight force). So you have the tension force acting up, and the weight force acting down, and their net total (algebraic sum) must be 960N .. So the tension force is ?

960 minus the downward force?
 
  • #8
No. Please pay heed to your plus and minus signs!

F_net =ma =960 N

the net force must be up (+), in the direction of the acceleration (+).

You have T (the rope tension) acting up (+), and W (the car's weight) acting down (-). T must be greater than W if the net force is up. Thus
T - W = 960. Solve for T, after first calculating W.
 
  • #9
Ah that makes sense. Thanks for the help. :-)
 

1. What is tension and why is it important?

Tension refers to the amount of force applied to an object, in this case a rope. It is important to know the tension a rope can withstand in order to ensure safety and prevent the rope from breaking or causing harm.

2. How is tension measured for a rope?

Tension is typically measured in units of force, such as pounds or newtons. It can be measured using a tension meter or by calculating the force applied to the rope using the formula F=ma (force = mass x acceleration).

3. What factors affect the amount of tension a rope can withstand?

The strength and material of the rope, the diameter and length of the rope, and the environment in which the rope is being used are all factors that can affect the tension a rope can withstand. Other factors include the method of tension application and the weight of the load being supported by the rope.

4. How do I determine the appropriate tension for a specific application?

The appropriate tension for a rope will depend on the specific application and the type of load being supported. It is important to consult with manufacturers or experts to determine the appropriate tension for your specific needs. Factors such as safety margins and potential hazards should also be taken into consideration.

5. Can a rope handle too much tension?

Yes, a rope can handle too much tension. Overloading a rope with excessive tension can cause it to break or fail, leading to potential safety hazards. It is important to know the maximum tension a rope can withstand and to never exceed it.

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