Power & Kinetic Energy Needed to Pull Wagon at 25km/hr

  • Thread starter Thread starter joepro
  • Start date Start date
  • Tags Tags
    Power
AI Thread Summary
To determine the power required to pull a wagon weighing 32,200 N at 25 km/h with a coefficient of rolling resistance of 0.200, the frictional force (Ff) can be calculated using the formula Ff = U * normal force. The normal force is equal to the weight of the wagon since it is not moving vertically, thus the normal force is 32,200 N. Once Ff is calculated, power can be found using the relationship between power, force, and velocity. Kinetic energy can also be determined using the appropriate formulas once the speed and mass are known. Understanding these relationships will help solve the problem effectively.
joepro
Messages
7
Reaction score
0
Hello, I am having a hard time figuring out some physics problems.

The problem states.

How much power is required to pull a wagon weighingi 32200N at the speed of 25.0km/hr f the coefficient of rolling resistance is 0.200? What is the kinetic energy of the wagon?
______KW
______J

Thanks for the help!
 
Physics news on Phys.org
What equations do you think you will need to solve this problem?
 
I knowI need Ff=UN but otherwise I do not understand how to put the acceleration problem together with the friction problem or where to even start.
 
joepro said:
I knowI need Ff=UN but otherwise I do not understand how to put the acceleration problem together with the friction problem or where to even start.

You don't need acceleration for this problem. You can get Ff using the formula. So now how does Power relate to force and velocity?
 
My U is .200 and I know that Ff=U * normal force. How do I find the normal force, then one I find the normal force what do I do to find the required power. I just need some steps and guidence. Thanks
 
joepro said:
My U is .200 and I know that Ff=U * normal force. How do I find the normal force, then one I find the normal force what do I do to find the required power. I just need some steps and guidence. Thanks

The normal force or the normal reaction is an upward force acting on the car. The only other force acting in the vertical direction is the weight which acts downwards. So if the car does not move up or down, then what is the normal force equal to?
 
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...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top