D= m/v
d= 6200/2296
density = about 2.7
Explanation:
the farther he buys the rod in the flame more is heated making the heat travel less and at a faster rate.
Answer:
r = 4.747 cm and h = 9.4925 cm
Explanation:
We know that volume of a cylinder is given as:
V = πr²h
Also, surface area is given as;
S = 2πr² + 2πrh
Where r is radius and h is height
Now, we are told that the volume is 672 cm³
Thus, πr²h = 672
Making h the subject gives;
h = 672/πr²
Putting 672/πr² for h in the surface area equation gives;
S = 2πr² + 2πr(672/πr²)
Factorizing gives;
S = 2π[r² + 672/πr]
Differentiating to get first derivative gives;
S' = 2π[2r - (672/πr²)]
Equating to zero gives;
2π[2r - (672/πr²)] = 0
4πr - 1344/r² = 0
4πr = 1344/r²
r³ = 1344/4π
r³ = 106.95212175775
r = ∛106.95212175775
r = 4.747 cm
So, since h = 672/πr²
Then, h = 672/π(4.747)²
h = 9.4925 cm
Answer:
Option C. Its image falls on the periphery of the retina, denser in rods
Explanation:
This can be explained as the photo receptors present in the outer periphery are more sensitive to light and enable us to see clearly dimly lit objects.
Also the peripheral vision is the the one on the retinal periphery which is highly rich in concentration of rods than cones and thus a dimly lit object at night with peripheral vision gives a clearer image of the object.
The central vision makes use of the central part, i.e., fovea which is dense with the concentration of cones, photo-receptors which enable us to see different colors and functions well in bright light.
Answer:
maximum power = 300 W
Explanation:
Ohm's law: Ohm's law state that the current flowing through a metallic conductor, is directly proportional to the potential difference applied across its end. mathematically it is expressed as,
V = IR............. Equation 1
Where V = potential difference, I = current, R = Resistance of the conductor.
If the power flowing through is gives as
W = 120I - 12I² ..................... Equation 2
To get the maximum power we differentiate of equation 2 and equate to zero
dW/dt = 0
120 - 24l = 0........................... equation 3
Making I the subject of the equation,
I = 120/24 = 5 A.
Suubstituting the value of I into Equation 2
W = 120 (5) - 12(5)²
W = 600 - 300
W = 300 W.
Therefore maximum power = 300 W