Select all the expressions below which represent a 20% discount off the price of an item that originally costs d dollars.
1 answer:
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Answer:
d = 2.45 meters
Explanation:
Mass of the ball, m = 0.5 kg
Radius of the circle, r = 0.16 m
The angular speed of the ball around the circle is,
The attached figure shows the whole scenario. Let is the force acting on the ball in tangential direction. The forces will balanced each other at equilibrium.
In horizontal direction,
................(1)
In vertical direction,
...............(2)
From equation (1) and (2) :
Also,
d = 2.45 meters
So, the value of d is 2.45 meters. Hence, this is the required solution.
The formula for the rotational kinetic energy is
where I is the moment of inertia. This is just mass times the square of the perpendicular distance to the axis of rotation. In other words, the radius of the propeller or this is equivalent to the length of the rod. ω is the angular velocity. We determine I and ω first.
ω = 573 rev/min * (2π rad/rev) * (1 min/60 s) = 60 rad/s
Then,
where I is the moment of inertia. This is just mass times the square of the perpendicular distance to the axis of rotation. In other words, the radius of the propeller or this is equivalent to the length of the rod. ω is the angular velocity. We determine I and ω first.
ω = 573 rev/min * (2π rad/rev) * (1 min/60 s) = 60 rad/s
Then,