<span>1.7 rad/s
The key thing here is conservation of angular momentum. The system as a whole will retain the same angular momentum. The initial velocity is 1.7 rad/s. As the person walks closer to the center of the spinning disk, the speed will increase. But I'm not going to bother calculating by how much. Just remember the speed will increase. And then as the person walks back out to the rim to the same distance that the person originally started, the speed will decrease. But during the entire walk, the total angular momentum remained constant. And since the initial mass distribution matches the final mass distribution, the final angular speed will match the initial angular speed.</span>
Answers:
a)
b)
Explanation:
a) The centripetal acceleration of an object moving in a uniform circular motion is given by the following equation:
Where:
is the angular velocity of the ball
is the radius of the circular motion, which is equal to the length of the string
Then:
This is the centripetal acceleration of the ball
b) On the other hand, in this circular motion there is a force (centripetal force ) that is directed towards the center and is equal to the tension () in the string:
Where is the mass of the ball
Hence:
This is the tension in the string
Explanation:
A student solving for the acceleration of an object has applied appropriate physics principles and obtained the expression :
Where
m = 7 kg
So, the correct step for obtaining a common denominator for the two fractions in the expression in solving for a is (a) and the value of a is :
Hence, the correct option is (a).