Recent content by kotchenski

Thank you, that was just what I was looking for.

The ramp is frictionless. I'm trying to understand what is happening with the sphere. If it is not rolling is it necessary to include the angular velocity? I'm asking because it it's not rolling then wouldn't it be zero? I have to do this so I can isolate the velocity to see how it changes for...

Homework Statement As of the past few hours I've been trying to make sense one how to calculate the velocity of a sphere that moves down a frictionless ramp. My biggest problem with this seems to be that I'm confusing myself with the linear velocity and the angular velocity. Note that the...

You purposely searched up that word didn't ya? :D, regardless thanks for your help!

Not entirely. I'm sorry if the translation is terrible but it's in danish. They ask for the time it takes for it to melt and then to vaporize. For vaporization I assume it would be in 4 stages: 1. Heating to reach the melting temperature. 2. Melting the wax. 3. Heating the liquid wax to the...

I assume there are two stages then, the first stage is when the wax is heating which is expressed by: Q= \frac{m C_p (s) (T_m-T_1)}{M} The second stage would be when the wax reaches the melting temperature and begins to melt and so I add that to the equation so that Q will be: Q= \frac{m...

I can see I said I would calculate the boiling, when I mean't I would calculate the melting. The candle is in solid phase and it's placed in a isolated room which has the temperature of 25 celsius. I will now light the candle and have to calculate the time it will take the 50g of solid wax to...

Homework Statement Assume that a wax candle with mass m at temperature T1 undergoes constant heat admission dQ/dt=Kp Assume: m=50g T1=25 celsius Kp=10W Calculate how long it will take for the wax to melt and vaporise during constant heat admission without any loss. Data: ρ=791...

Homework Statement A person performs an exercise where he pulls a rubber band stuck in a wall to later return it to its resting position. The two movements forward and backward, is equivalent to one practice cycle. They both happen in a horrizontal plane with a constant velocity of v=0.5ms-1...

So if I use that Fnet(x)=Fo*cos(θ)-μn And that Fnet(x)<0, then the value of θ<arctan(μ), and therefor I'm applying a force Fo that is less than gravity? Wouldn't that technically mean the box is not moving and is being held back by the friction?

Homework Statement The object is a box with a given mass m. Our person has the choice between pushing the box with a horizontal force, or pulling the box with a wire with an angle of θ=30o. The magnitude of Fo is the force vector he affects the box with in both cases. Is it possible (If you...

Thank you, it really helps :). There's only 2 questions left, and I'm having trouble with one of them. What is the optimized angle θ he could have pulled the box with to achieve maximum acceleration? I decided here to use the equation for a that we just found and defined it as a...

Like this? n=mg-Fo*sin(θ) ma=Fo*cos(θ)-μ(mg-Fo*sin(θ) ma=Fo*cos(θ)-μmg+μFo*sin(θ) a=(Fo*cos(θ))/m -μg + (μFo*sin(θ))/m

Thank you I think I got it now. There is one final question that I can't seem to understand. Is it possible (if you can freely choose a value for θ) to keep the box moving without applying a force Fo that is greater than the gravity on the box? I don't think you can because then it...

I think I understand it. It's in a vertical equilibrium, which means \SigmaFy=0 Which then yields: n=mg-F*sin(θ) Now I know that the object accelerates to the right thereby it's horizontal acceleration is given as: Fnet(x)=ma Which is the same as: ma=F*cos(θ)-μn Now I think I get...