Question

1. Analogies exist between rotational and translational physical quantities. Identify the rotational term analogous to each of the following: acceleration, force, mass, work, translational kinetic energy, linear momentum, impulse.

2. Explain why centripetal acceleration changes the direction of velocity in circular motion but not its magnitude.

Answer 1

1) a α, m I, W=F.d W =τ . θ,

2) a = v²/r

Step-by-step explanation:

1) The amounts of rotational and translational motion are related

acceleration is

a = d²x / dt²

linear displacement is equivalent to angular rotation, therefore angular acceleration is

α = d²θ / dt²

force in linear motion is equivalent to moment in endowment motion

F = m a

τ = I α

the mass is the inertia of the translation, in rotational motion the moment of inertia is the rotational inertia

I = m r²

Work is defined by W = F. d

in rotation it is defined by W = τ . θ

The linear momentum is p = mv

the angular momentum L = I w

momentum the linear motion is I = F dt

in the rotation it is I = τ dt

2) The velocity is a vector therefore it has modulus and direction, linear acceleration changes the modulus of velocity, whereas circular motion changes the direction (the other element of the vector).

`a_(c)`Ac = v²/r