For this problem, we use the derived equations for rectilinear motion at constant acceleration. The equations used for this problem are:
a = (v - v₀)/t
2ax = v² - v₀²
where
a is the acceleration
x is the distance
v is the final velocity
v₀ is the initial velocity
t is the time
The solution is as follows;
a = (60mph - 30 mph)/(3 s * 1 h/3600 s)
a = 36,000 mph²
2(36,000 mph²)(x) = 60² - 30²
Solving for x,
x = 0.0375 miles
The correct answer to the question above is that the magician is seeking the wavelength of the standing wave. The part of a standing sound wave, which is its wavelength, the magician is seeking when playing a musical note of a specific pitch.
Answer:

Explanation:
We must use conservation of linear momentum before and after the collision, 
Before the collision we have:

where these are the masses are initial velocities of both players.
After the collision we have:

since they clong together, acting as one body.
This means we have:

Or:

Which for our values is:

Answer:
Explanation:
m₂ is hanging vertically and m₁ is placed on inclined plane . Both are in limiting equilibrium so on m₁ , limiting friction will act in upward direction as it will tend to slip in downward direct . Tension in cord connecting the masses be T .
For equilibrium of m₁
m₁ g sinα= T + f where f is force of friction
m₁ g sinα= T + μsx m₁ g cosα
m₁ g sinα - μs x m₁ g cosα = T
For equilibrium of m₂
T = m₂g
Putting this value in equation above
m₁ g sinα - μs x m₁ g cosα = m₂g
m₂ = m₁ sinα - μs x m₁ cosα
The emissivity of the earth is 0.5
The emissivity of the earth is calculated by the Stefan's law
