Answer:t=0.81 s
Explanation:
Given
Penguin slides down with constant velocity of 3.57 m/s
as the Penguin Slides with constant velocity therefore
is zero on Penguin
![F_{net}=mg\sin \theta -f_r](https://tex.z-dn.net/?f=F_%7Bnet%7D%3Dmg%5Csin%20%5Ctheta%20-f_r)
friction Force
![f_r=\mu mg](https://tex.z-dn.net/?f=f_r%3D%5Cmu%20mg)
coefficient of Kinetic friction
![mg\sin \theta =\mu mg](https://tex.z-dn.net/?f=mg%5Csin%20%5Ctheta%20%3D%5Cmu%20mg)
![\tan \theta =\mu](https://tex.z-dn.net/?f=%5Ctan%20%5Ctheta%20%3D%5Cmu%20)
![\mu =\tan 9.85=0.45](https://tex.z-dn.net/?f=%5Cmu%20%3D%5Ctan%209.85%3D0.45)
after reaching on floor final velocity of penguin will be zero after time t
thus
![v=u+at](https://tex.z-dn.net/?f=v%3Du%2Bat)
here ![a=\mu g](https://tex.z-dn.net/?f=a%3D%5Cmu%20g)
(deceleration)
![0=3.57-4.41\times t](https://tex.z-dn.net/?f=0%3D3.57-4.41%5Ctimes%20t)
![t=\frac{3.57}{4.41}=0.809](https://tex.z-dn.net/?f=t%3D%5Cfrac%7B3.57%7D%7B4.41%7D%3D0.809)
![t=0.81 s](https://tex.z-dn.net/?f=t%3D0.81%20s)
Answer:
7.9![\frac{gr}{cm^3}](https://tex.z-dn.net/?f=%5Cfrac%7Bgr%7D%7Bcm%5E3%7D)
Explanation:
When we put the metal piece in the liquid (which is in the graduated cylinder), how much it goes up is equal to the volume of the piece we inserted.
So now we know that the volume of that piece of unknown metal is 7mL (which is the same as 7
).
Density is
.
So the density of that piece of metal is ![\frac{55.3g}{7cm^3}](https://tex.z-dn.net/?f=%5Cfrac%7B55.3g%7D%7B7cm%5E3%7D)
Which leaves us with a final density of 7.9![\frac{gr}{cm^3}](https://tex.z-dn.net/?f=%5Cfrac%7Bgr%7D%7Bcm%5E3%7D)
Answer:
D. Electromagnetic Induction.
Explanation:
I think, I do think.. that it is D.
Wouldn't it be simple to divide 5 from 20, that would equal 4.
4 earthworms per square meter.