Work done by the rope and power of electric motor

AI Thread Summary
The discussion revolves around two physics problems: calculating the work done by a rope pulling a box and determining the power of an electric motor lifting water. For the first problem, the work done can be calculated using the formula W = F * d * cos(θ), where F is the tension in the rope, d is the distance moved, and θ is the angle of the rope with the horizontal. The second problem involves calculating power using the formula P = W/t, where W is the work done lifting the water and t is the time taken. Participants are encouraged to share their attempts and thoughts on the problems to facilitate better assistance. The thread emphasizes collaborative problem-solving in physics.
ramma_akash
Messages
1
Reaction score
0
Hello friends, pls help me.I need the answer to the following questions

1) A massive box is dragged along a horizontal floor by a rope.The rope makes an angle of 30 degrees with the horizontal.Find the work done if the tension in the rope is 200N and the box is moved through a distance of 10m.(Plz tell me the procedure with formulas).

2)Find the power of an electric motor if it lifts 200kgs of water in 5mins from a well of 120m depth.(Plz tell me the procedure with formulas)
 
Physics news on Phys.org
ramma_akash said:
Hello friends, pls help me.I need the answer to the following questions

1) A massive box is dragged along a horizontal floor by a rope.The rope makes an angle of 30 degrees with the horizontal.Find the work done if the tension in the rope is 200N and the box is moved through a distance of 10m.(Plz tell me the procedure with formulas).

2)Find the power of an electric motor if it lifts 200kgs of water in 5mins from a well of 120m depth.(Plz tell me the procedure with formulas)
Hi ramma_akash and welcome to PF,

We will be more than happy to help you work through your problems, but first your have to some some effort. What have you attempted thus far? What are your thoughts on the questions?
 
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...
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...
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...
Back
Top