Kinetic energy = mass time squared speed divided by 2
W=mv^2/2 = 50*10*10/2 = 2500 J
Answer:
Heat Input = Work Output (at 100% efficiency)
ΔQ = ΔW
(you cannot get something for nothing)
Answer:
the volume is 0.253 cm³
Explanation:
The pressure underwater is related with the pressure in the surface through Pascal's law:
P(h)= Po + ρgh
where Po= pressure at a depth h under the surface (we assume = 1atm=101325 Pa) , ρ= density of water ,g= gravity , h= depth at h meters)
replacing values
P(h)= Po + ρgh = 101325 Pa + 1025 Kg/m³ * 9.8 m/s² * 20 m = 302225 Pa
Also assuming that the bubble behaves as an ideal gas
PV=nRT
where
P= absolute pressure, V= gas volume ,n= number of moles of gas, R= ideal gas constant , T= absolute temperature
therefore assuming that the mass of the bubble is the same ( it does not absorb other bubbles, divides into smaller ones or allow significant diffusion over its surface) we have
at the surface) PoVo=nRTo
at the depth h) PV=nRT
dividing both equations
(P/Po)(V/Vo)=(T/To)
or
V=Vo*(Po/P)(T/To) = 0.80 cm³ * (101325 Pa/302225 Pa)*(277K/293K) = 0.253 cm³
V = 0.253 cm³
Answer:
![t=12.25\ seconds](https://tex.z-dn.net/?f=t%3D12.25%5C%20seconds)
Explanation:
<u>Diagonal Launch
</u>
It's referred to as a situation where an object is thrown in free air forming an angle with the horizontal. The object then describes a known path called a parabola, where there are x and y components of the speed, displacement, and acceleration.
The object will eventually reach its maximum height (apex) and then it will return to the height from which it was launched. The equation for the height at any time t is
![x=v_ocos\theta t](https://tex.z-dn.net/?f=x%3Dv_ocos%5Ctheta%20t)
![\displaystyle y=y_o+v_osin\theta \ t-\frac{gt^2}{2}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20y%3Dy_o%2Bv_osin%5Ctheta%20%5C%20t-%5Cfrac%7Bgt%5E2%7D%7B2%7D)
Where vo is the magnitude of the initial velocity,
is the angle, t is the time and g is the acceleration of gravity
The maximum height the object can reach can be computed as
![\displaystyle t=\frac{v_osin\theta}{g}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20t%3D%5Cfrac%7Bv_osin%5Ctheta%7D%7Bg%7D)
There are two times where the value of y is
when t=0 (at launching time) and when it goes back to the same level. We need to find that time t by making ![y=y_o](https://tex.z-dn.net/?f=y%3Dy_o)
![\displaystyle y_o=y_o+v_osin\theta\ t-\frac{gt^2}{2}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20y_o%3Dy_o%2Bv_osin%5Ctheta%5C%20t-%5Cfrac%7Bgt%5E2%7D%7B2%7D)
Removing
and dividing by t (t different of zero)
![\displaystyle 0=v_osin\theta-\frac{gt}{2}](https://tex.z-dn.net/?f=%5Cdisplaystyle%200%3Dv_osin%5Ctheta-%5Cfrac%7Bgt%7D%7B2%7D)
Then we find the total flight as
![\displaystyle t=\frac{2v_osin\theta}{g}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20t%3D%5Cfrac%7B2v_osin%5Ctheta%7D%7Bg%7D)
We can easily note the total time (hang time) is twice the maximum (apex) time, so the required time is
![\boxed{t=24.5/2=12.25\ seconds}](https://tex.z-dn.net/?f=%5Cboxed%7Bt%3D24.5%2F2%3D12.25%5C%20seconds%7D)