The answer to question one is A.
The answer to question two is A.
The answer to question three is D.
Answer:
4
Explanation:
We know that intensity I = P/A where P = power and A = area through which the power passes through.
Now, let the initial intensity of the speaker be I₀ and its initial power be P₀. Since the intensity is increased by a factor of 4, the new intensity be I and new power be P.
So, I = P/A and I₀ = P₀/A
Now, if I = 4I₀,
P/A = 4P₀/A
P = 4P₀
Now, energy E = Pt, where t = time. So, P = E/t and P₀ = E₀/t
Substituting P and P₀ into the equation, we have
P = 4P₀
E/t = 4E₀/t
E = 4E₀
Since the energy is four times the initial energy, the energy output increases by a factor of 4.
I believe the acceleration would be 5m/s
All you would need to do is divide the final speed by the time it took to get there. I am only about 80 sure this answer is correct, so take my advise only if you feel comfortable.
Answer:
The height reached is 20m, The time taken to reach 20m is 2 seconds
Explanation:
Observing the equations of motion we can see that the following equation will be most helpful for this question.
We are given initial velocity, u
We know that the stone will stop at its maximum height, so final velocity, v
Acceleration, a
And we are looking for the displacement (height reached), s
Substitute the values we are given into the equation
Rearrange for s
s = -20 (The negative is just showing direction, it can be ignored for now)
The height reached is 20m
Use a different equation to find the time taken
Substitute in the values we have
Rearrange for t
t = 2s
The time taken to reach 20m is 2 seconds
Answer:
The value is
Explanation:
From the question we are told that
The mass of the ice cube is
The temperature of the ice cube is
The mass of the copper cube is
The final temperature of both substance is
Generally form the law of thermal energy conservation,
The heat lost by the copper cube = heat gained by the ice cube
Generally the heat lost by the copper cube is mathematically represented as
The specific heat of copper is
Generally the heat gained by the ice cube is mathematically represented as
Here L is the latent heat of fusion of the ice with value
So
=>
So
=>