Since the law of gravitation is an inverse square law if you
quadruple the radius the f will drop by a factor of 16 SO the object would
weigh 200/16 = 12.5N
In other words, as the distance, or radius, quadruples the
weight becomes 1/16 of the original weight. Just plug in 4 for r and when you
square it you get 16. The numerator is 1 so that is how the weight becomes
1/16.
KNOWN: Long, 30mm-diameter cylinder with embedded electrical heater; power required
to maintain a specified surface temperature for water and air flows.
FIND: Convection coefficients for the water and air flow convection processes, hw and ha,
respectively.
ASSUMPTIONS: Flow is cross-wise over cylinder which is very long in the direction
normal to flow.
The convection heat rate from the cylinder per unit length of the cylinder has
the form
q' = h*(pi*D)*(Ts-Tinf)
and solving for the heat transfer convection coefficient, find
Water
hw = q'/((pi*D)*(Ts-Tinf))
hw = (38*10^3 W/m) / ((pi*(0.030m))*(80-25)C)=
7330.77314 W/m^2K
Air
ha = (400W/m) / ((pi*(0.030m))*(80-25)C)=<span>
77.166033 </span> W/m^2K
COMMENTS: Note that the air velocity is 10 times that of the water flow, yet
hw ≈ 95 × ha.
These values for the convection coefficient are typical for forced convection heat transfer with
liquids and gases
Watter is a better convective heat transfer media than air
Answer:
The correct option is;
The graduate cylinder with more water has more thermal energy because it is holding more water molecules
Explanation:
Given that the thermal energy of the system is the energy possessed by the system by virtue of the increased motion of the particles by virtue of a transfer of heat, when the content of the system is heated
The thermal energy, Q is given by the following equation;
Q = Mass, m × The specific heat capacity, C × The change in temperature, ΔT
Given that the graduated cylinder with more water has more mass and therefore, more water molecules, than the cylinder with less water, the cylinder with more water has more thermal energy.
Answer:
Explanation:
Coin slide across the floor and finally comes to stop with an increase in temperature.
We can conclude that the coin interacted with one or more object which reduces its velocity.
- It is also possible that coin stop due to friction which elevates the coin temperature by converting some part of its energy into thermal energy
