Hanging Block

This demonstration again shows the resolution of forces on an object.  Though it appears the block is sitting on the ramp, it is actually being supported by the two strings.  Calculations can be done to determine the forces involved.

Setup:

Setup the equipment as shown in the first photo above.  It should appear that the block rests on the ramp.

Remove the ramp to show that the block is hanging (as shown in the second photo).

Notes:

Ensure that the strings attached to the block are perpendicular to each other. If the strings will slide along the hooks so that the angle between them is no longer ninety degrees, the angle of the stand is no longer equal to any angle when decomposing the tensions into horizontal and vertical components.

Courses Used In:

• PHY 10111

• PHY 10310

• PHY 10410

• PHY 30210

Discussion and Polling Questions:

• What is the net force on the system?

• What are the individual forces acting on the system?

• What is the tension in string 1 if you calculate it from a free-body diagram? Does it match the weight of its hanging block?

• What is the tension in string 2 if you calculate it from a free-body diagram? Does it match the weight of its hanging block?

Equipment Needed:

• Ring Stands

• 1 kg Block

• String

• Two Pulleys

• Ramp

• Protractor

• Masses and Mass Hangers