A bumblebee buzzes past you at 3 m/s. The frequency of the hum made by its wings is 152 Hz. Assume the speed of sound to be 342
2 answers:
Answer: 153 Hz
Explanation:
The apparent frequency heard by the listener is given by Doppler effect which states that apparent frequency heard by listener varies if the there is relative motion between the source and the listener.
In the given situation, observer is stationary and source of sound is approaching the listener. Thus,
You might be interested in
Answer:
<em>Correct choice: b 4H</em>
Explanation:
<u>Conservation of the mechanical energy</u>
The mechanical energy is the sum of the gravitational potential energy GPE (U) and the kinetic energy KE (K):
E = U + K
The GPE is calculated as:
U = mgh
And the kinetic energy is:
Where:
m = mass of the object
g = gravitational acceleration
h = height of the object
v = speed at which the object moves
When the snowball is dropped from a height H, it has zero speed and therefore zero kinetic energy, thus the mechanical energy is:
When the snowball reaches the ground, the height is zero and the GPE is also zero, thus the mechanical energy is:
Since the energy is conserved, U1=U2
For the speed to be double, we need to drop the snowball from a height H', and:
Operating:
Dividing [2] by [1]
Simplifying:
Thus:
H' = 4H
Correct choice: b 4H
Answer:
The points 2 and 4 should be connected.
Explanation:
To complete the circuit, we need to connect the two points which when connected, encompass the battery and the bulb in the circuit. The points 2 and 4 do the job, since they connect the terminal of the battery and the terminal of the bulb, and thus complete the circuit.
Therefore, the choice C is correct.
