A man of mass 70kg rides a bicycle of mass 15kg at a steady speed of 4

AI Thread Summary
To calculate the power developed by a cyclist riding uphill, first determine the potential energy gained over a distance of 20 meters with a height increase of 1 meter. The total mass of the cyclist and bicycle is 85 kg, and the gravitational force is 9.81 m/s², which helps in calculating the work done against gravity. Next, find the time taken to travel 20 meters at a steady speed of 4 m/s, which is 5 seconds. Finally, apply the power formula P = F * V, considering the constant resistance of 20N to find the total power output. This approach effectively combines energy concepts with motion dynamics to solve the problem.
Doubell
Messages
29
Reaction score
0

Homework Statement



a man of mass 70kg rides a bicycle of mass 15kg at a steady speed of 4 ms-1 up a road which rises 1.0 m for every 20m of its length. what power is the cyclist developing if there is a constant resistance to motion of 20N

Homework Equations



(P= F*V) , ( p= W/t)

The Attempt at a Solution

 
Physics news on Phys.org


I suggest you work with a distance of 20 m. Figure out the height and potential energy gained over that distance. Figure out the time it takes to go 20 m. Then you will be in a position to use one of your power formulas.
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Calculating the Component of the weight that acts along a line
Replies
8
Views
3K
Calculating Power from Mass, Speed and Height - 250W
Replies
10
Views
2K
How do I calculate the magnitude of initial acceleration?
Replies
9
Views
6K
Why do bicycles require more pedaling force at higher speeds?
Replies
12
Views
2K
How Much Power Does a Cyclist Develop Climbing a Slope with Resistance?
Replies
1
Views
2K
Force exerted on bicycle to maintain cosntant speed
Replies
2
Views
10K
Calculate Cyclist's Speed in Race: Energy-Work Problem Solution
Replies
3
Views
3K
Cyclist coasting down a hill cons. of energy
Replies
4
Views
3K
Calculating Work and Energy for a Cyclist Riding Up a Slope
Replies
6
Views
4K
Power output of cyclist up slope at costant speed
Replies
7
Views
4K

Hot Threads

Recent Insights

Back
Top