Answer:
The magnitude of angular acceleration is .
Explanation:
Given that,
Initial angular velocity,
When it switched off, it comes o rest,
Number of revolution,
We need to find the magnitude of angular acceleration. It can be calculated using third equation of rotational kinematics as :
So, the magnitude of angular acceleration is . Hence, this is the required solution.
Answer:
The mass rate of the cooling water required is:
Explanation:
First, write the energy balance for the condensator: The energy that enters to the equipment is the same that goes out from it; consider that there is no heat transfer to the surroundings and kinetic and potential energy changes are despreciable.
Where w refers to the cooling water and s to the steam flow. Reorganizing,
Write the difference of enthalpy for water as Cp (Tout-Tin):
This equation will let us to calculate the mass rate required. Now, let's get the enthalpy and Cp data. The enthalpies can be read from the steam tables (I attach the tables I used). According to that, and can be calculated as:
.
The Cp of water at 25ºC (which is the expected average temperature for water) is: 4.176 . If the average temperature is actually different, it won't mean a considerable mistake. Also we know that , so let's work with the limit case, which is to calculate the minimum cooling water mass rate required (A higher one will give a lower temperature difference as a result). Finally, replace data:
Answer:
Explanation:
Mass of the losing player with its all equipment is given as
M = 86 kg
Net force applied on him by another player is given as
F = 780 N
also we know that acceleration of the losing player is given as
now by Newton's 2nd law we will have
Voltage = (current) x (resistance)
= (19 A) x (14 ohms) = 266 volts .
Note: Be careful using that thing !
It's dissipating
I² R = (19 A)² x (14 ohms) = 5,054 watts ! ! !
That's an awful lot of power for a blow-dryer !
The dryer is certainly not using very much of that power to run the fan.
Most of it is being used to heat air. 5 kilowatts is more power than most
toasters or microwave ovens use, so please be careful with how much of
your hair or skin you expose to that hot-air blast. You could probably cook
a meatloaf with it.
mass of the box = 20 kg
force of friction on the box due to surface
similarly kinetic friction on it
now the weight of the suspended block will be
so here the weight of the suspended block is less than the limiting friction on it
So here we will say that friction will counter balance the weight of the suspended block and it will not move at all
So acceleration of the box will be zero