Angular acceleration of a wheel formula

AI Thread Summary
The formula for angular acceleration (α) can be derived from the known tangential acceleration (at) and the wheel's diameter (d) using the equation α = (2at)/d. The tangential speed (vt) can also be expressed in terms of the diameter as vt = (2ω)/d, where ω is the angular speed. The discussion emphasizes the relationship between tangential and angular values, particularly in the context of a wheel attached to a moving body, such as a car. It highlights the importance of understanding these conversions to solve problems involving angular acceleration. The conversation reflects a focus on applying known parameters to derive the necessary equations.
MrPotatoHead
Messages
2
Reaction score
0

Homework Statement



What is the formula for angular acceleration, when the wheel's diameter, speed, acceleration and distance are known.

Homework Equations





The Attempt at a Solution

 
Physics news on Phys.org
The hard part is realizing that the speed the wheel is moving at (I'm assuming it's a wheel attached to a moving body like a car driving on the road) is equal to the tangential speed of a particle on the end of the wheel. Same can be said about acceleration.

So, then you simply convert between tangential and angular values, you said diameter is known, so these are given in terms of diameter d (with d=2r) as
\alpha=\frac{2a_{t}}{d}, \omega=\frac{2v_{t}}{d}
 
MrPotatoHead said:

Homework Statement



What is the formula for angular acceleration, when the wheel's diameter, speed, acceleration and distance are known.

Homework Equations





The Attempt at a Solution


Welcome to the PF.

You are asking for an equation for acceleration, when the acceleration is known?
 
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top