The heating element of a water heater in an apartment building has a maximum power output of 37 kw. four residents of the building take showers at the same time, and each receives heated water at a volume flow rate of 11x10-5 m3/s. if the water going into the heater has a temperature of 14°c, what is the maximum possible temperature of the hot water that each showering resident receives

maximum possible temperature is 34.088°C

Explanation:

Given data

power output Q = 37 kW

volume flow rate = 11 x 10^-5 m3/s

temperature t = 14°C

to find out

maximum possible temperature T

solution

we can say

total water volume  = 4 residents  × volume flow

total water volume = 4 × 11 x 10^-5  = 44 × 10^-5 m³/s

so we say total water mass = 1000 × volume

total water mass = 1000 kg/m³ ×  44 × 10^-5  

total water mass = 0.44 kg

we know

dQ/dt = (dm/dt)× (S)× ( T - t)

so here we know specific heat of water S = 4.186 joule/gram °C

37 = 0.44 × 4.186 × (T-14)

T = 34.088°C

maximum possible temperature is 34.088°C

answer: the correct answer is 1.

explanation: there are various process in which a radioactive nuclei decays:

1) alpha decay: in this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. the mass number is reduced by 4 units.

2) electron capture: in this decay process, a parent nuclei absorbs an electron and gets converted into a neutron. simply, a proton and an electron combines together to form a neutron. mass number does not change in this process.

3) gamma ray emission: it is a decay process in which an unstable nuclei gives excess energy by a spontaneous electromagnetic process. this decay releases . this process does not change the mass number.

4) positron emission: it is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. this is also known as -decay. in this the mass number remains same.

from the above information, we see that only alpha-decay is producing a change in the mass number of the nucleus.

i'm on my way to history not a mistory.