Concepts Of Physics MCQ Edition [Volume 1]
- Exam
- Concepts Of Physics MCQ Edition [Volume 1]
- Subject
- Physics
- Chapter
- Work and Energy
Concepts Of Physics MCQ Edition [Volume 1] · Physics · Work and Energy
The athlete Emily Davis won the 100 m sprint gold medal at London...
The athlete Emily Davis won the sprint gold medal at London Olympic 2012 setting a new Olympic record of . Assume that she achieved her maximum speed in a very short time and subsequently ran the race with that speed till she crossed the line. Take her mass to be . Assuming that the track, the wind etc. offered an average resistance of one tenth of her weight, determine the power Emily Davis had to exert to maintain uniform speed.
Options
- A
- B
- C
- D
Correct answer
A.
Step-by-step solution
Given distance and time .
Since the maximum speed is achieved in a very short time, the uniform speed of the athlete is:
The average resistance force offered by the track and wind is one-tenth of her weight. Taking :
To maintain a uniform speed, the athlete must exert a force equal to the resistance force. The power exerted by the athlete is:
Rounding to the nearest integer gives .
Since the maximum speed is achieved in a very short time, the uniform speed of the athlete is:
The average resistance force offered by the track and wind is one-tenth of her weight. Taking :
To maintain a uniform speed, the athlete must exert a force equal to the resistance force. The power exerted by the athlete is:
Rounding to the nearest integer gives .