Answer:
speed = 3.95 m/s
Explanation:
area = π x radius^2
area = π x (2.67 x 10^-3)^2
volume flow rate = area x speed
volume / time = area x speed
density = mass / volume
volume = mass / density
<u>mass / (density x time) = area *speed</u>
mass flow rate = mass / time
<u>mass flow rate / density = area x speed</u>
6.55 x 10^-2 / 740 = pi * (2.67 x 10^-3)^2 * speed
speed =8.8514 x 10-5 /2.2396 x 10-5 m/s
speed = 3.95 m/s
This question is not about physics science.
The answer is: option <span>a. Five-year-old children have longer attention spans than three-year-old children.
It is the attention ability what let the older children to stay longer in one location instead of being moving between different activities. The younger children who cannot keep their attention long time in a same activity entertain themselves by changing activities.
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Answer:
(a) The final angular speed is 12.05 rad/s
(b) The time taken to turn 5.5 revolutions is 5.74 s
Explanation:
Given;
number of revolutions, θ = 5.5 revolutions
acceleration of the wheel, α = 20 rpm/s
number of revolutions in radian is given as;
θ = 5.5 x 2π = 34.562 rad
angular acceleration in rad/s² is given as;
(a)
The final angular speed is given as;
(b) the time taken to turn 5.5 revolutions is given as
We assign the variables: T as tension and x the angle of the string
The <span>centripetal acceleration is expressed as v²/r=4.87²/0.9 and (0.163x4.87²)/0.9 = </span><span>T+0.163gcosx, giving T=(0.163x4.87²)/0.9 – 0.163x9.8cosx.
</span>
<span>(1)At the bottom of the circle x=π and T=(0.163x4.87²)/0.9 – .163*9.8cosπ=5.893N. </span>
<span>(2)Here x=π/2 and T=(0.163x4.87²)/0.9 – 0.163x9.8cosπ/2=4.295N. </span>
<span>(3)Here x=0 and T=(0.163x4.87²)/0.9 – 0.163x9.8cos0=2.698N. </span>
<span>(4)We have T=(0.163v²)/0.9 – 0.163x9.8cosx.
</span><span>This minimum v is obtained when T=0 </span><span>and v verifies (0.163xv²)/0.9 – 0.163x9.8=0, resulting to v=2.970 m/s.</span>
