Physics 11
A 62kg cyclist changes the speed of a 12kg bicycle from 8.2m/s to 12.7m/s. Determine the work done.
I've already answered & gotten this question correct, however it made me confused about the concept.
I found Ek. & Ek to find change in Ek which was 3479.85. He did work against both friction & inertia & yet this one formula covered both & I didn't have to add anything together. Why not? As far as I understood, to get Work total you need to do the formula for each work (friction & inertia) then add.
Thank you!! ☺

No, the work done was the difference in kinetic energies, assuming the work to overcome friction at each speed was constant.
posted by bobpursley

So does that mean if I have work against friction & acceleration I can use that one formula to cover both? :)
posted by Kayla

Yes, if the friction involved in attaining different speeds was the same....in real life, it is not. Friction of air is dependent on velocity squared as a rule of thumb.
posted by bobpursley

Ok, that's super helpful thank you very much!! :)
posted by Kayla
Respond to this Question
Similar Questions

Physics 11
A 62kg cyclist changes the speed of a 12kg bicycle from 8.2m/s to 12.7m/s. Determine the work done. I used change in energy = work to find work against inertia which was 3479.85 Then I used V^2=V.^2 + 2ad to get ad=47.025 I then 
physics
What is the kinetic energy of a 62kg cyclist if she is moving on her bicycle at 8.2 m/s? 
Physics
A cyclist starts from rest and coasts down a 6.5∘{\rm ^\circ} hill. The mass of the cyclist plus bicycle is 95kg{\rm kg} . The cyclist has traveled 270m{\rm m} .What was the net work done by gravity on the cyclist? How fast 
physics
How fast must a cyclist climb a 4.0 degree hill to maintain a power output of 0.35 hp? Neglect work done by friction, and assume the mass of cyclist plus bicycle is 83 kg. 
As physics
A cyclist moves along a horizontal road. She pushes on the pedals with a constant power of 250W. The mass of the cyclist and bicycle is 85kg. The total drag force is 0.4V^2, where v is the speed of the cyclist. i) Calculate the 
applied physics
A cyclist and her bicycle have a combined mass75.okg. If the frictional force acting against the of the bicycle is 23.5, what force must the cyclist apply to maintain a constant velocity? 
Physics
A cyclist and her bicycle have a combined mass of 75.0kg. If the frictional force acting against the motion of the bicycle is 23.5N, what force must the cyclist apply to maintain a constant velocity? 
physics
A 50.0kg cyclist on a 10.0kg bicycle speeds up from 5.0m/s to 10.0m/s , the total kinetic energy before acceleratingis 750, and after acceleratingis 3000, how much work is done to increase the kinetic energy of the cyclist and the 
Science (Physics)
A 33.3 kg cyclist is riding a 10.7 kg bicycle at a velocity of 7.0 m/s. If the cyclist applies a brake that applies a force of 42.7 N, what is the time required for the cyclist to come to a stop? 
Physics
Aa particular bicycle is 25% effificent in converting the energy of a cyclist to mechanical energy (that is, she puts in four times as much energy as she gets out). if a cyclist is travelling along a pathway at a constant speed of