How much work? Given speeds and mass

  • Thread starter Thread starter ital_dj
  • Start date Start date
  • Tags Tags
    Mass Work
AI Thread Summary
The discussion focuses on calculating the work done by an Olympic triathlete accelerating from 5 m/s to 10 m/s on a bicycle with a total mass of 105 kg. The key equation for work is identified as W = Fd, where force is derived from mass and acceleration. Participants clarify that gravitational energy is not a factor in this scenario, prompting a focus on kinetic energy changes. The solution involves calculating the difference in kinetic energy, using the formula W = ΔKE, rather than solving for distance directly. The final takeaway is that work can be determined by subtracting the initial kinetic energy from the final kinetic energy.
ital_dj
Messages
31
Reaction score
0

Homework Statement


How much work is done by an Olympic triathlete who accelerates herself on her bicycle (combined mass of 105kg) from 5m/s to 10m/s


Homework Equations


W = mg\Deltad


The Attempt at a Solution


Tried solving for d, and plugging in.
 
Physics news on Phys.org
Your equation would apply if there was gravitational energy involved, but in this question there isn't. Work here is defined as W = Fd where F = ma.
 
But still, how would I solve for d?
 
Use kinematics to solve for a and d simultaneously.
 
W = delta(KE)

All you need to do is subtract her final kinetic energy from her initial kinetic energy to find the answer.
 

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
View full post »

Similar threads

Misunderstanding Work-energy theorem and center of mass properties
Replies
7
Views
2K
Solving for Work Done When Accelerating a Mass
Replies
3
Views
785
How Much Work Is Done by an Olympic Triathlete Accelerating on Her Bicycle?
Replies
2
Views
2K
How much work done by friction when a box w/apparent mass...?
Replies
4
Views
2K
Does the mass of an object affect its inertia?
Replies
6
Views
2K
Work Check - Centripetal force - Finding Tension in a Rope
Replies
8
Views
3K
Calculating Mass of Cannon Ball with Given Velocity Using Work-Energy Theorem
Replies
3
Views
1K
Work Done by Gravity and Tension in a Pulley System
Replies
3
Views
2K
Work and energy of an object on a ice slope
Replies
7
Views
1K
How to Determine the Work Done by the Rope on a Sledge?
Replies
5
Views
2K

Hot Threads

Recent Insights

Back
Top