Answer:
ωf' =5.16 rad/s
Explanation:
Given that
Initial angular speed ,ωi= 125 rev/min ( 1 rev/min = 0.10472 rad/s)
ωi=13.08 rad/s
The angular speed after 1 min ,ωf= 0.7 x 125 = 87.5 rev/min
ωf=9.1 rad/s
Lets angular acceleration =α
We know that
ωf = ωi + α t
Now by putting the values in the above equation we get
9.1 = 13.08 + α x 60 ( after 1 min ,t= 60 s)
α = -0.066 rad/s²
The angular speed after 2 min
ωf' = ωi + α t
ωf' =13.08 - 0.066 x 2 x 60 rad/s
ωf' =5.16 rad/s
Therefore the angular speed after 2 min will be 5.16 rad/s.
Answer:
That is not true all objects fall at the same speed excepts things like feathers or paper.
Answer:
the thickness of the dam should be the same if the level of water does not change.
Explanation:
the thickness of dam depends on the pressure of water that has to withstand.
Since the pressure exerted by the water depends only on the depth of the lake and not the length of the lake
P =1/2 *ρ*g*h ,
where P= pressure exerted by the water on the dam, ρ= density of water , g= gravity , h= depth of the lake
Then if the lake were smaller and the depth remains the same, the thickness of the dam should be the same
The energy a charge has due to its position relative to other charges.
