Angular Momentum

Question 1

is a fundamental concept in physics that describes the rotational equivalent of linear momentum. It helps to understand the motion of objects that are rotating or revolving around an axis.

Answer 1

Angular Momentum

Question 2

It resist the changes in object’s orientation while rotating.

Answer 2

Angular Momentum

Question 3

A solid sphere of mass 4 kg and radius 0.3m rotates 3 rad/s about an axis through its center. What is its angular momentum?

Answer 3

L = 𝟎.𝟒𝟑𝟐 𝑘𝑔𝑚^2/s

Question 4

A uniform thin rod of length 2m and mass 5 kg is rotated about an axis perpendicular to the rod and passing through one of its ends. Find the angular momentum if the rod rotates about 5 rad/s.

Answer 4

I = 33.33𝒌𝒈𝒎^𝟐/s

Question 5

is a fundamental principle in physics that states the total angular momentum of a system remains constant if no external torques act on the system.

Answer 5

Conservation of angular momentum

Question 6

A figure skater is spinning with an initial angular velocity of 2.0 rad/s with arms extended. The moment of inertia with arms extended is 5.0 kg·m². When the skater pulls their arms in, their moment of inertia decreases to 2.0 kg·m². What is the skater’s new angular velocity?

Answer 6

𝝎_𝟐=𝟓 𝒓𝒂𝒅/𝒔

Question 7

A planet of mass 𝑀 orbits a star in an elliptical orbit. At the closest point to the star the distance is 𝑟_1​ =1.0×10^7 km and the planet’s speed is 𝑣_1=40 km/s. At the farthest point (apastron), the distance is 𝑟_2 = 3.0×10 7 km. What is the speed of the planet at apastron, assuming no external torques act on the system? Express your answer in km/s.

Answer 7

𝒗_𝟐=𝟏𝟑.𝟑𝟑 𝒌𝒎/𝒔