Answer: 60m/s
Explanation:
The wavespeed is the distance covered by the wave in one second. It is measured in metre per second, and represented by the symbol V
Wavespeed (V) = Frequency F x wavelength λ
i.e V = F λ
In the first case:
Wavespeed = 30 m/s
Frequency of sound = 6Hz
Wavelength = 5m
In the second case:
Wavespeed = ?
Frequency of sound = (2x 6Hz = 12Hz)
Wavelength = 5m (remains constant)
Apply V = F λ
Wavespeed = 12 Hz x 5m
Wavespeed = 60m/s
Therefore, when frequency is doubled, the speed is also doubled. Thus, the new speed of the wave is 60m/s
Answer:
The velocity after 2 seconds can be found through:
V = u +a*t
Where V is final velocity, u is initial velocity, a is acceleration and t is time.
V = 0 + 2* 2= 4 meters/second
The distance (s) can be found through:
V^2= u^2 +2*a* s
Where V is final velocity, u is initial velocity, a is acceleration.
4^2= 0^2 + 2 *2*s
16= 0 + 4s
s= 4 meters
Distance (s) can also be found through:
s= ut + 1/2 at^2
s= 0+ 1/2 *2*2^2= 1 *2*2
s= 4 meters
Explanation:
Answer:
The average power the woman exerts is 0.5 kW
Explanation:
We note that power, P = The rate at which work is done = Work/Time
Work = Energy
The total work done is the potential energy gained which is the energy due to vertical displacement
Given that the vertical displacement = 5.0 m, we have
Total work done = Potential energy gained = Mass, m × Acceleration due to gravity, g × Vertical height, h
m = 51 kg
g = Constant = 9.81 m/s²
h = 5.0 m
Also, time, t = 5.0 s
Total work done = 51 kg × 9.81 m/s²× 5 m = 2501.55 kg·m²/s² = 2501.55 J
P = 2501.55 J/(5 s) = 500.31 J/s = 500.31 W ≈ 500 W = 0.5 kW.
If the spaceship's Physicist happens to be hanging out of one side
of the ship, and he measures the speed of the photons as they pass
him and leave the ship, he'll see them passing him at 'c' ... the speed
of light.
When those photons pass somebody who happens to be in their
path, and he decides to measure their speed, he'll see them move
past him at 'c' ... the speed of light.
It doesn't matter whether the observer who measures them is
moving, or at what speed.
And it doesn't matter what source the photons come from, or
whether the source is moving, or at what speed.
And it doesn't matter what the photons' wavelength/frequency is ...
anything from radio to gamma rays.
The photons pass everybody at 'c' ... the speed of light.
Yes, I hear you. That can't be true. It's crazy.
Maybe it's crazy, but it's true.
While Jane is running has a kinetic energy, which is Ek = 1/2*m*v^2 where m is mass and v is velocity When she grabs a vine, she is going to change the kinetic energy to potential energy.
We know that potential energy is given by Ep = m*g*h where m is mass, g is gravity constant and h is height
So while running the kinetic energy is Ek = 1/2 * m * 5.2^2 = 13.52*m
Then all that energy is used to swing upward and gain potential energy
Ep = m*g*h = Ek = 13.52*m
m*9.8*h = 13.52*m
h = 13.52/9.8 = 1.38 meters
So Jane will swing 1.38 meters upward
