Calculating Effect of Wind on Sprint Time: Why?

  • Thread starter Thread starter heraclius
  • Start date Start date
  • Tags Tags
    Time Wind
Click For Summary

Homework Help Overview

The problem involves calculating the effect of wind on a student's sprint time for a 100m race. The student typically completes the sprint in 15 seconds, and the question explores how an increase in speed due to favorable wind conditions affects her time.

Discussion Character

  • Exploratory, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants discuss the student's normal speed and the conversion between different units of speed. There are attempts to calculate the new sprint time after accounting for the wind's effect.

Discussion Status

Some participants have provided calculations and reasoning regarding the speed conversions and the impact of the wind on sprint time. There is a recognition of the need for clarity in the calculations, but no consensus has been reached on the final answer.

Contextual Notes

Participants note the importance of understanding the underlying physics of speed and time, as well as the constraints of the forum's policy against providing complete solutions.

heraclius
Messages
10
Reaction score
0
Hello guys, could you please help me to solve this problem?

A student normally needs 15 seconds for a 100m sprint. One day favorable wind conditionshelp her to increase her speed by 2km//h.
What is her time now?

A) aprx. 13,8 sec.
B) aprx. 13,6 sec.
C) aprx. 13 sec.
D) aprx. 14,2 sec.

Could you explain why ?
 
Physics news on Phys.org
What is her normal speed?
 
heraclius said:
Hello guys, could you please help me to solve this problem?

A student normally needs 15 seconds for a 100m sprint. One day favorable wind conditionshelp her to increase her speed by 2km//h.
What is her time now?

A) aprx. 13,8 sec.
B) aprx. 13,6 sec.
C) aprx. 13 sec.
D) aprx. 14,2 sec.

Could you explain why ?

Her speed, in m/sec is 100 m in 15 sec or 6.67 m/sec.

First, convert that to km/hr.

100 m is 0.1 km and there are 3600 sec in an hr.

So, her speed in km/hr is 0.1 km/(15/3600 hr) which is 24 km/hr.

Now, add the increase due to the wind: 24 km/hr + 2 Km/hr = 26 km/hr

That's 26000 m in 3600 sec. Or 7.22 m/sec.

How long does it take to run 100m at the rate of 7.22 m/sec?

100 m / (7.22 m/sec) = ~13.8 sec, so the answer is A).
 
Thank you very much!
 
Mensanator said:
Her speed, in m/sec is 100 m in 15 sec or 6.67 m/sec.

First, convert that to km/hr.

100 m is 0.1 km and there are 3600 sec in an hr.

So, her speed in km/hr is 0.1 km/(15/3600 hr) which is 24 km/hr.

Now, add the increase due to the wind: 24 km/hr + 2 Km/hr = 26 km/hr

That's 26000 m in 3600 sec. Or 7.22 m/sec.

How long does it take to run 100m at the rate of 7.22 m/sec?

100 m / (7.22 m/sec) = ~13.8 sec, so the answer is A).
It is against the policy in this forum to provide complete answers to posters' questions.
 

Similar threads

Undergrad Why is WR for 4x100m relay less than 4 times WR for 100m sprint.
  • · Replies 2 ·
Replies
2
Views
4K
Undergrad Damped oscillator with changing mass
  • · Replies 131 ·
5
Replies
131
Views
9K
Graduate Superdense coding for sending 2 qubits at a time?
  • · Replies 1 ·
Replies
1
Views
3K
Undergrad Why doesn't mass of a pendulum effect its time period
  • · Replies 4 ·
Replies
4
Views
6K
Computer languages tend to be transient
  • · Replies 44 ·
2
Replies
44
Views
6K
High School Time-reversal of an unknown quantum state
  • · Replies 1 ·
Replies
1
Views
2K
Graduate Calculate Gravitational Effects without Time, Acceleration or Velocity
  • · Replies 1 ·
Replies
1
Views
2K
Graduate The expanding universe isn't in our neighborhood
  • · Replies 3 ·
Replies
3
Views
3K
Undergrad Dependence of friction on area.
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Can You Calculate Time Change Over 40 Centuries?
  • · Replies 5 ·
Replies
5
Views
3K