A horizontal platform in the shape of a circular disk rotates on a frictionless bearing about a vertical axle through the center
1 answer:
Answer:
10.93 rad/s
Explanation:
If we treat the student as a point mass, her moment of inertia at the rim is
So the system moment of inertia when she's at the rim is:
Similarly, we can calculate the system moment of inertia when she's at 0.456 m from the center
We can apply the law of angular momentum conservation to calculate the post angular speed when she's 0.456m from the center:
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Answer:
a) The answer is 11,7m
b) The time it takes to fall will be shorter
Explanation:
We will use the next semi-parabolic movement equations
Where g(gravity acceleration)=9,81m/s^2
Also Xi, Hi and Viy are zero, as the stones Billy-Jones is kicking stay still before he moves them, so we take that point as the reference point
The first we must do is to find how much time the stones take to fall, this way:
Then t=1,54s
After that we need to replace t to find H, this way
Then H=11,7m
b) The stones will fall faster as the stones will be kicked harder, it will cause the stones move faster, it means, more horizontal velocity. In order to see it better we could assume the actual velocity is two times more than it is, so it will give us half of the time, this way:
Then, t=0,77
Answer:
Explanation:
Given that,
The distance between two spheres, r = 25 cm = 0.25 m
The capacitance, C = 26 pF = 26×10⁻¹² F
Charge, Q = 12 nC = 12 × 10⁻⁹ C
We need to find the work done in moving the charge. We know that, work done is given by :
Put all the values,
So, the work done is .