Answer:
<em>8hours 45minutes</em>
Explanation:
Amount of heat energy used up by the electric substance = heat gained by the water.
Amount of heat energy used up by the electric substance = Power * Time
heat gained by the water. = mcΔt
m is the mass of the water in kg
c is the specific heat capacity
Δt is the change in temperature
Given parameters
Power = 5kW = 5000W
mass of water m = 500kg
c = 4200J/kgC
Δt = 100°C - 25°C = 75°C
Required
Time taken
Substituting the given parameters into the formula
Pt = mcΔt
5000t = 500*4200*75
5000t = 157,500,000
Divide both sides by 5000
t = 157,500,000/5000
t = 31,500 secs
t = (31,500/3600)hrs
t = 8.75hours
t = 8hours 45minutes
<em>Hence it takes 8hours 45minutes to heat 500 kg of water in the tank from 25c to 100c</em>
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Answer:
The protons which are present are positively charged that attracts and pulls the electrons closer to the water molecule. Thus, the water molecule's negative charge is distributed all over the atom of oxygen, producing a substantial negative charge.
Explanation:
The nucleus of the oxygen atom is made up of 8 neutrons and 8 protons. The protons which are present are positively charged that attracts and pulls the electrons closer to the water molecule.
Thus, the water molecule's negative charge is distributed all over the atom of oxygen, producing a substantial negative charge. While, as electrons have drifted away from water molecules, the atom of hydrogen are left with just a partially positive charge.
Answer:
D. Cars have the same velocity at one instant of time between dots 4 and 5.
Explanation:
The two cars will eventually have the same velocity and it occurs between 4 and 5. Velocity is normally defined as displacement over time. This shows that a change in the value of either time or displacement will affect the value of the velocity. Thus, at a given time between the points 4 and 5, the two cars have the same value of velocity.
Answer:
The right answer is D) the total momentum of the system is 0.047 kg · m/s toward the right.
Explanation:
Hi there!
The total momentum of the system is given by the sum of the momentum vectors of each cart. The momentum is calculated as follows:
p = m · v
Where:
p = momentum.
m = mass.
v = velocity.
Then, the momentum of the system will be the momentum of cart A plus the momentum of cart B (let´s consider the right as the positive direction):
mA · vA + mB · Vb
0.450 kg · 0.850 m/s + 0.300 kg · (- 1.12 m/s) = 0.047 kg · m/s
The right answer is D) the total momentum of the system is 0.047 kg · m/s toward the right.
