Explanation:
The total energy of the system remains conserved. It just converts from one form of energy to another.
The battery of the cell phone contains chemicals. As the electricity is passed through the cell phone, the electrical energy is converted to chemical energy. As she notices that the phone is warm and after the battery has been fully charged and the student unplugs her cell phone, the phone vibrates when a message arrives, this shows the conversion of chemical energy to mechanical energy, thermal energy etc.
Hence, we can say that the correct option is (b).
Answer:
So the sound intensity level they would experience without the earplugs is 110.32dB.
Explanation:
Given data
Sound intensity by factor =215
Sound intensity level =87 dB
To find
Sound intensity level they would experience without the earplugs
Solution
First we need to find the new sound intensity level
So

The dB can be calculated as:

Substitute the given values

So the sound intensity level they would experience without the earplugs is 110.32dB.
Answer:
The initial speed of the cork was 1.57 m/s.
Explanation:
Hi there!
The equation of the horizontal position of the cork in function of time is the following:
x = x0 + v0 · t · cos θ
Where:
x = horizontal position at time t.
x0 = initial horizontal position.
v0 = initial speed of the cork.
t = time.
θ = launching angle.
If we place the origin of the frame of reference at the launching point, then x0 = 0.
We know that at t = 1.25 s, x = 1.50 m. We also know the launching angle so we can solve the equation of horizontal position for the initial speed, v0:
x = v0 · t · cos θ
x / t · cos θ = v0
v0 = 1.50 m / (1.25 s · cos (40.0°)
v0 = 1.57 m/s
The initial speed of the cork was 1.57 m/s.
Answer:
The answer is already given... it's 31.25 cm