Rotational mecahnics Definition and 13 Threads

If I understand correctly : The angular velocity vector has two components: one along ##\text{-ve z-axis}## and one along ##\text{-ve x-axis} ## So the motion can be considered to be two rotations:(some animation might help) Rotation about ##\text{z-axis}## with angular speed...

Hello! I was wondering if anyone knew a good explanation behind the physical reason for torque. As in why a force applied from a greater distance to the center of rotation is better at turning an object than a force applied closer to the center. The question seems obvious, but all I've been able...

Well, I tried plugging the data in the formula. I know that ##\vec a_b = 0; \vec \omega=3 rad/s ; \vec r## can be calculated using trigonometry. Then I also know that ##v_{relx}= 10 cm/s##, ##a_{relx}=15 cm/s^2##, ##\vec {\dot{\omega}}=-10 rad/s^2##. But how do I get ##v_{rely}## and...

Homework Statement A uniform cylindrical wheel of mass ##m_{1}## and radius ##R_{1}## rotates with angular velocity ##\omega_{1}##. It lies a certain distance (along the same axis) from a static wheel of radius ##R_{2}## and mass ##m_{2}##. The wheels are then pushed against each other with a...

I have a doubt in my mind regarding moment of inertia.in my textbook a question is somewhat like this The center of a disc of mass 'M' and radius 'R' is at a distance 'd' (here 'd' >'R') from a certain point 'O'.what is the moment of inertia of the disc about an axis perpendicular to the plane...

Homework Statement A rod of mass ##M## and length ##l## is pivoted at the center(##O##) in horizontal position. An object of equal mass(having velocity ##v##) falls vertically on the rod at distance ##\frac{l}{4}## from ##O## and sticks to it. Find the angular velocity of the rod just after...

Homework Statement ) The pulley system in Figure 1.b consists of two pulleys of radii a and b rigidly fixed together, but free to rotate about a common horizontal axis. The weight W hangs from the axle of a freely suspended pulley P, which can rotate about its axle. If section A of a rough...

Homework Statement The flag is d=2mm thick and D=30 m long. We roll the flag and stick the short side of the flag (long side is 30m, short side's length is not given) on the ceiling so that the flag unwraps back to the ground. Flag is M=30kg. 1. Find the time it takes to 10 m of the flag to get...

1. a uniform rod of mass m and length l is placed horizontally on a smooth horizontal surface.An impulse is applied at one end perpendicular to the length of the rod. what is the velocity of centre of mass and angular velocity of rod just after the impulse is applied.

Hello, I am a second year undergrad student majoring in Astronomy and Computer Science. I am having a hard time with my physics courses for the following reasons: 1) SmartPhysics is the text we use (if you can call it a text...). Basically it is an online HW and "pre-lecture" system that...

Lets say i have a rod (length = L) hinged at one end (A).It is initially at rest.Now if an impulse (J) acts on the other end (B),can i conserve the angular momentum about A(the hinge)? that is can i write: JL=Iw?(I=moment of inertia,w=angular velocity) this is what i saw in the book. My Doubt...

Homework Statement Estimate the time it takes a pencil of length L=10 cm to hit the ground if initially the pencil makes an angle of 0.001 rad with the vertical. Take the gravitational acceleration to be 10m/s2 Details and assumptions Assume that the pencil is just a thin solid rod with...