Answer:
Either heat added or mechanical work done.
Explanation:
Since he found stirring rod on the desk and a cigarette lighter. This means that the beaker was probably either heated with the aid of fire from the lighter.
Also, the stirring rod could have been used to stir the water which will increase the kinetic energy which also means an increase in temperature.
Thus, it's either heat was added or mechanical work was done as a result of stirring.
The relationship between speed of a wave w, frequency f and wavelength
![\lambda](https://tex.z-dn.net/?f=%5Clambda)
is
![v = \lambda f](https://tex.z-dn.net/?f=v%20%3D%20%5Clambda%20f)
For the wave of our problem,
![\lambda = 5 m](https://tex.z-dn.net/?f=%5Clambda%20%3D%205%20m)
and f=60 Hz, so its speed is
5-14 m/s in 3 seconds
a=vf-vi/t
a=14-5/3
a=9/3
a=3 m/s^2
Answer:35.2 ft
Explanation:
Given
height of stick =4 ft
shadow length =2.8 ft
Angle of elevation of sun is
![tan\theta =\frac{4}{2.8}](https://tex.z-dn.net/?f=tan%5Ctheta%20%3D%5Cfrac%7B4%7D%7B2.8%7D)
let the height of tree be h
as
will remain same thus
![tan\theta =\frac{h}{24.64}](https://tex.z-dn.net/?f=tan%5Ctheta%20%3D%5Cfrac%7Bh%7D%7B24.64%7D)
![\frac{4}{2.8}=\frac{h}{24.64}](https://tex.z-dn.net/?f=%5Cfrac%7B4%7D%7B2.8%7D%3D%5Cfrac%7Bh%7D%7B24.64%7D)
h=35.2 ft