Answer:
A. The athlete isn’t doing any work because he doesn’t move the weight.
Explanation:
We must remember the definition of work, which says that work is equal to the product of mass by the distance displaced. In this case, the athlete only does work when he lifts the weight from the ground to the point where he holds the weight suspended.
So when he's holding the weight, he doesn't do any work.
The correct answer to the question is : D) 352.6 m/s.
CALCULATION :
As per the question, the temperature is increased from 30 degree celsius to 36 degree celsius.
We are asked to calculate the velocity of sound at 36 degree celsius.
Velocity of sound is dependent on temperature. More is the temperature, more is velocity of sound.
The velocity at this temperature is calculated as -
V = 331 + 0.6T m/s
= 331 + 0.6 × 36 m/s
= 331 + 21.6 m/s
= 352.6 m/s.
Here, T denotes the temperature of the surrounding.
Hence, velocity of the sound will be 352.6 m/s.
