Answer:
The final angular velocity is 20rad/s
Explanation:
We are given;
mass, m = 12 kg
radius, r = 0.25 m
Work done;W = 75 J
Moment of inertia of cylinder, I = (1/2) mr²
Thus,
I = (1/2) x 12 x 0.25² = 0.375 kg.m²
Now, from work energy theorem,
Work done = Change in kinetic energy
So, W = KE_f - KE_i
Now, Initial Kinetic Energy (KE_i) = 0
Final Kinetic Energy; KE_f = (1/2)Iω²
So, KE_f = (1/2) x 0.375 x ω²
KE_f = 0.1875 ω²
Now, W = 75 J
Thus,
From, W = KE_f - KE_i, we have;
75 = 0.1875 ω² - 0
75 = 0.1875 ω²
ω² = 75/0.1875
ω² = 400
ω = √400
ω = 20 rad/s
The average power supplied to the box by friction while it slows from 13 m/s to 11.5 m/s is 3.24 W.
<h3>Acceleration of the box</h3>
The acceleration of the box is calculated as follows;
vf² = vi² + 2as
a = (vf² - vi²)/2s
a = (11.5² - 13²) / (2 x 8.5)
a = -2.16 m/s²
<h3>Time of motion of the box</h3>
The time taken for the box to travel is calculated as follows;
a = (vf - vi)/t
t = (vf - vi) / a
t = (11.5 - 13) / (-2.16)
t = 0.69 s
<h3>Average power supplied by the friction</h3>
P = Fv
P = (ma)(vf - vi)
P = (1 x -2.16) x (11.5 - 13)
P = 3.24 W
Thus, the average power supplied to the box by friction while it slows from 13 m/s to 11.5 m/s is 3.24 W.
Learn more about average power here: brainly.com/question/19415290
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Answer:
because they have enough water
Explanation:
When an object move with a constant velocity
and there are forces acting on it, this is called unbalanced force. The forces
acting on an object is a net force, which is capable of changing speed and/or
direction of motion of an object. However,
the two forces acting on the object can be added together to give the resultant force, which is a
single force that has the same effect on the object as all the individual
forces acting together.
