We can solve the problem by using Snell's law, which states

where

is the refractive index of the first medium

is the angle of incidence

is the refractive index of the second medium

is the angle of refraction
In our problem,

(refractive index of air),

and

(refractive index of carbon disulfide), therefore we can re-arrange the previous equation to calculate the angle of refraction:

From which we find
Answer:
(D) The weight of the space station and the gravitational force of the space station on the earth.
Explanation:
In both A and B , both the forces act in the same direction ( downwards ) , so they can not be action- reaction force .
In the option C , weight of a astronaut can only be reaction force of gravitational force exerted on the earth by astronaut. Both astronaut and the earth pull each other with equal and opposite force. So option D is correct.
Answer:
a) 36 m
b) 64 m
Explanation:
Given:
v₀ = 0 m/2
v = 12 m/s
t = 6 s
Find: Δx
Δx = ½ (v + v₀) t
Δx = ½ (12 m/s + 0 m/s) (6 s)
Δx = 36 m
The track is 100 m, so the sprinter still has to run another 64 m.
Answer:

Explanation:
We are given that


d=1.9 cm=
Using 1m=100 cm
We have to find the electric field strength.

Using the formula





Mass of electron,m

Substitute the values


Answer:
98.15 lb
Explanation:
weight of plane (W) = 5,000 lb
velocity (v) = 200 m/h =200 x 88/60 = 293.3 ft/s
wing area (A) = 200 ft^{2}
aspect ratio (AR) = 8.5
Oswald efficiency factor (E) = 0.93
density of air (ρ) = 1.225 kg/m^{3} = 0.002377 slugs/ft^{3}
Drag = 0.5 x ρ x
x A x Cd
we need to get the drag coefficient (Cd) before we can solve for the drag
Drag coefficient (Cd) = induced drag coefficient (Cdi) + drag coefficient at zero lift (Cdo)
where
- induced drag coefficient (Cdi) =
(take note that π is shown as n and ρ is shown as
)
where lift coefficient (Cl)=
=
= 0.245
therefore
induced drag coefficient (Cdi) =
=
= 0.0024
- since the airplane flies at maximum L/D ratio, minimum lift is required and hence induced drag coefficient (Cdi) = drag coefficient at zero lift (Cdo)
- Cd = 0.0024 + 0.0024 = 0.0048
Now that we have the coefficient of drag (Cd) we can substitute it into the formula for drag.
Drag = 0.5 x ρ x
x A x Cd
Drag = 0.5 x 0.002377 x (293.3 x 293.3) x 200 x 0.0048 = 98.15 lb