To solve this problem we will apply the concepts related to the Doppler Effect. The Doppler effect is the change in the perceived frequency of any wave movement when the emitter, or focus of waves, and the receiver, or observer, move relative to each other.
Mathematically it can be described as

Where,
v = Speed of sound
f' = Reflected frequency
f = Emitted Frequency
= Speed of the object
Assuming that the speed of the medium is the speed of sound of 343m / s, we will then have that:


Output can not be greater than input because the conversion of energy can not be greater than 100%.
It will be 4 times of original thus maximum speed would be 80cm/s
Answer:
-3.396 m/s or 3.465 m/s
Explanation:
v = Speed of sound in air = 343 m/s
= Relative speed of the singer
f = Observed frequency
f' = Actual frequency
1% change can mean 
From the Doppler effect equation we have

The velocity is -3.396 m/s
when 

The velocity is 3.465 m/s
Answer:
Explanation:
The formula for time period of a pendulum is given as follows :
T = 2π
l is length of pendulum and g is acceleration due to gravity .
So time period of pendulum is not dependent on the mass of the pendulum . If time period is same and length is also the same then acceleration due to gravity will also be the same . Hence the acceleration due to gravity at distant planet will be same as that on the earth.