PHYS 101 Lecture Notes - Mechanical Advantage, Momentum

• School: McGill University
• Department: Physics
• Course: PHYS 101
• Professor: Kenneth Ragan

Document Summary

It is possible for a small force to exert a greater torque on a system than a larger force. Moment of inertia depends on where the mass is located. Example: a cylindrical satellite (m = 3600 kg, r = 4. 0 m) is spun up" with four rocket motors firing tangentially. What is the force of each rocket if the satellite is spun up from zero to 32 rpm in 5. 0 minutes: w o = 0 rad/s, t = ia , a = d, i = 1/3 etc. /d t, a = 3*2p /0. 20 = 94. 2 rad/s^2. Wheelbarrows, screwdrivers, and bicycle pedals all give mechanical advantage that can be understood using the ideas of torque. Why are sit-ups with your hands behind your head more difficult: putting mass at larger distance form pivot point (increased than arms stretched in front of you? moment of inertia) and therefore harder to turn at hips.