Answer:
B train!
Explanation:
A train travelled at 40 km/hr. (120/3)
B train traveled at 45 km/hr (180/4)
Its because the molecules in the solid structures are very close to each other and rigidly packed, thus due to this quantum structure they have pretty awesome speed of sound in them
Answer:

Explanation:
given,
Radius of the solid rod, R = 5.3 cm
Electric field strength,E = 22 kN/C
Let the volume charge density be ρ
From Gauss law

ε₀ is the permitivity of free space
R is the radius of the rod
and also,

ρ is the volume charge density



Hence, the volume charge density is equal to 
Answer:
The answer to the question is
The distance d, which locates the point where the light strikes the bottom is 29.345 m from the spotlight.
Explanation:
To solve the question we note that Snell's law states that
The product of the incident index and the sine of the angle of incident is equal to the product of the refractive index and the sine of the angle of refraction
n₁sinθ₁ = n₂sinθ₂
y = 2.2 m and strikes at x = 8.5 m, therefore tanθ₁ = 2.2/8.5 = 0.259 and
θ₁ = 14.511 °
n₁ = 1.0003 = refractive index of air
n₂ = 1.33 = refractive index of water
Therefore sinθ₂ =
=
= 0.1885 and θ₂ = 10.86 °
Since the water depth is 4.0 m we have tanθ₂ =
or x₂ =
=
= 20.845 m
d = x₂ + 8.5 = 20.845 m + 8.5 m = 29.345 m.
Answer:
m = 1 kg
Explanation:
Given that,
The force constant of the spring, k = 39.5 N/m
The frequency of oscillation, f = 1 Hz
The frequency of oscillation is given by the formula as formula as follows :

So, the mass that is attached to the spring is 1 kg.