Recitation Worksheet J Solutions

Recitation Worksheet J Solutions - Worksheet J Conservation...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Worksheet J: Conservation of energy. 1. A small bead of mass m = 30 g hangs at one end of a string of length l = 10 cm. The other end is attached to the ceiling as shown in the figure below. The bead is pulled up, so the string makes an angle θ 0 = 70 ° with the vertical, and released from there. Air resistance is negligible. a. Is mechanical energy conserved? Why? Yes. The only force doing work is gravity, which is a conservative force. (The tension on the string does zero work because it is always perpendicular to the trajectory). b. Write the potential energy of the bead as a function of . Take the potential energy to be zero at the lowest point of the trajectory. () ( 1 c o s) Um g l =− (for details, see lecture notes) c. Fill in the table below with the appropriate values of the mechanical energy, the potential energy, the kinetic energy and the speed of the bead at different angles. 32 2 (30 10 kg)(9.8 m/s )(10 10 m) 0.0294 J 2.94 mJ ( ) (2.94 mJ)(1 cos ) (70 ) 19 mJ (because the initial kinetic energy is zero) and always has the same value.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 4

Recitation Worksheet J Solutions - Worksheet J Conservation...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online