All except C, feelings are not physical.
Answer:
Option B
Solution:
As per the question:
Heat produced at the rate of 10 W
The resistor R and 2R are in series.
Also, in series, same current, I' passes through each element in the circuit.
Therefore, current is constant in series.
Also,
Power,
When current, I' is constant, then
P' ∝ R
Thus

P' = 20 W
Answer:
a. an increase in the mass on the spring.
Explanation:
T = 2π/ω = 2π/√(k/m) = 2π√(m/k)
2π is a constant
as m is in the numerator, increasing mass will increase the period.
Answer:
the speed of the sound in the air is 343.3 m/s
Explanation:
The computation of the speed of the sound in the air is shown below:
As we know that
Speed = Distance ÷ time
So, here speed be 515 m
And, the time is 1.50 seconds
So, the speed of the sound is
= 515 m ÷ 1.50 seconds
= 343.3 m/s
hence, the speed of the sound in the air is 343.3 m/s