Answer:
2633.7 s
Explanation:
From the question,
Heat lost by the water heater = Heat gained by the water
Applying,
P = cm(t₂-t₁)/t.................. Equation 1
Where P = power of the heat, c = specific heat capacity of water, m = mass of water, t₁ = initial temperature, t₂ = final temperature, t = time
make t the subject of the equation
t = cm(t₂-t₁)/P.............. Equation 2
From the question,
Given: c = 4190 J/kgK, P = 3.5 kW = 3500 W, m = 40 kg, t₁ = 20°C, t₂ = 75°C
Substitute these values into equation 2
t = 4190×40(75-20)/3500
t = 9218000/3500
t = 2633.7 s
Answer:
- 2.7 x 10^-6 J
Explanation:
q1 = 1 nC at x = 0 cm
q2 = - 1 nC at x = 1 cm
q3 = 4 nC at x = 2 cm
The formula for the potential energy between the two charges is given by

where r be the distance between the two charges
By use of superposition principle, the total energy of the system is given by



U = - 2.7 x 10^-6 J
Answer:
the smallest radius of the circular path is 8.1 km
Explanation:
The computation of the smallest radius of the circular path is given below:
Given that
V = Velocity = 201 m/s
a_c = acceleration = 5 m/s^2
radius = ?
As we know that
a_c = V^2 ÷ r
5 = 201^2 ÷ r
r = 201^2 ÷ 5
= 8,080.2 g
= 8.1 km
Hence, the smallest radius of the circular path is 8.1 km
Answer:
The width of the central bright fringe on the screen is observed to be unchanged is 
Explanation:
To solve the problem it is necessary to apply the concepts related to interference from two sources. Destructive interference produces the dark fringes. Dark fringes in the diffraction pattern of a single slit are found at angles θ for which

Where,
w = width
wavelength
m is an integer, m = 1, 2, 3...
We here know that as
as w are constant, then

We need to find
, then

Replacing with our values:


Therefore the width of the central bright fringe on the screen is observed to be unchanged is 
Answer:
The second one is correct.
Explanation:
=