Answer:
option E
Explanation:
given,
diameter = 4 mm
shutter speed = 1/1000 s
diameter of aperture = ?
shutter speed = 1/250 s
exposure time to the shutter time

N is the diameter of the aperture and t is the time of exposure
now,


inserting all the values

N₂² = 4
N₂ = 2 mm
hence , the correct answer is option E
Answer:
A. The bird watcher followed the south trail a distance of five kilometers in 45 minutes.
Answer:
m = 788.2[kg]
Explanation:
The potential energy of a body is defined as the product of mass by gravitational acceleration by height. And it can be calculated by means of the following equation.

where:
Epot = potential energy = 63405 [J]
m = mass [kg]
g = gravity acceleration = 9.81[m/s²]
h = elevation = 8.2[m]
Now replacing:
![63405=m*9.81*8.2\\m=788.2[kg]](https://tex.z-dn.net/?f=63405%3Dm%2A9.81%2A8.2%5C%5Cm%3D788.2%5Bkg%5D)
I am almost sure it it (c)
Answer:
10.3 cm³
Explanation:
From the question given above, the following data were obtained:
Original volume (V₁) = 10 cm³
Initial temperature (θ₁) = 20 °C
Final temperature (θ₂) = 50 °C
Cubic expansivity (γ) = 10¯³ K¯¹
Final volume (V₂) =?
γ = V₂ – V₁ / V₁(θ₂ – θ₁)
10¯³ = V₂ – 10 / 10( 50 – 20)
10¯³ = V₂ – 10 / 10(30)
10¯³ = V₂ – 10 / 300
Cross multiply
10¯³ × 300 = V₂ – 10
0.3 = V₂ – 10
Collect like terms
0.3 + 10 = V₂
10.3 = V₂
V₂ = 10.3 cm³
Thus, the volume at 50 °C is 10.3 cm³