:<span> </span><span>Under the assumption that a cell is made up of two concentric spheres you find the surface are of the inside sphere which will be your A.
You already have your separation and dielectric constant so just use the formula you stated towards the end of your question and you get 8.93x10^-11 Farads which is about 89pF</span>
Answer:
2600 m
Explanation:
A fathometer produces a sound wave and then detects the echo. It takes 3.5 seconds for the echo to reach the ship, so that means it takes half the time (1.75 seconds) to reach the ocean floor.
The speed of sound in seawater is approximately 1500 m/s, so the depth of the ocean at that point is:
d = 1500 m/s × 1.75 s
d = 2625 m
Rounding to two significant figures, the depth is approximately 2600 m.
Answer:
C
Explanation:
To melt the alcohol
Heat needed = M . L = 2 . 25 = 50 kcal
To warm up the alcohol
Heat needed = M . sp. ht. . ∆t = 2 . 0.6 . 100 = 120 kcal
Total heat needed = 170 kcal
Assuming that 0.6 kcal/ kg / ˚C is the specific heat and that the answer is wanted in kcal ( a rather odd unit to be in use here.)
The centripetal acceleration of an object is given by the relation,

where Ac = centripetal acceleration =
R = radius of rotation = 15 m
V = speed of astronaut
Hence, 
solving this we get, V = 38.34 m/s