Physics Rotational Motion In a rotating motion there

Physics

Rotational Motion In a rotating motion there are two acceleration vectors involved: - Tangential acceleration, at - Centripetal acceleration, ac ,

Radian Measure From the figure, S is the length along the path. Or the size of the central angle and the radius of circular path. must in radians must be rad/s 2

Sample Problem 1. A car is moving on a circular racetrack of radius 150 ft. It sweeps out an angle of 200 degrees. How far has it travelled? Solution:

Exercises 1. A propeller starts from rest and accelerates at 120 rev/s 2 for 4 seconds. What is its final angular velocity in rev/sec? in rev/min? 2. A helicopter tail rotor starts with an initial angular velocity of 15 rev/sec and decelerates at a rate of 2 rev/s 2 until it comes to rest. Through how many revolutions has the rotor turned while it comes to rest?

Exercises 3. A plane is circling in a circular pattern of radius 15, 000 ft. It sweeps out an angle of 340 degrees. How far has it travelled? 4. A race car is moving on a circular racetrack of radius 800 ft. It is accelerating at a rate of 10 ft/sec 2. What is its angular acceleration in rev/sec?

Archimedes’ Principle

Archimedes Principle Three possibilities to happen: 1. It may sink. 2. It stay on the actual depth. 3. It may rise.

Bouyant Force The pressure at the bottom surface of the subject.