Recent content by Steve4Physics

Yes. Post #26 was intended for the OP - in case they didn't understand the underlying physics. My school physics teacher (from many decades ago) expressly forbade us from using the term 'suction'. The lesson stuck! Yes. That's not unreasonable.

You may have some misundestandings - even about the forces in Fig. 1. Try working through this: Consider the simple Fig. 1 setup. Assume the piston is of negligible weight and is stationary and in equilibrium. Take atmospheric pressure as 101kPa (=101,000 N/m2). Assume friction, surface...

Some general comments... Units for ρ and g are essential. If the correct units aren’t clear, sometimes terrible things happen! E.g. see https://spacemath.gsfc.nasa.gov/weekly/6Page53.pdf The intended meanings of F1, F2 and F3 are not clear. Are they meant to represent: - the force of the water...

The OP has incorrectly drawn the Post #1 diagram, believing (wrongly) that ##\vec s = \vec a + \vec b##. Then they have ignored their diagram and used: which gives the correct value. The OP should note thast the question specifically says “By constructing vector diagrams, find the magnitudes...

It would be best to sort out part a) first. There are some mistakes. The first two are: 1) The diagram is wrong. When adding vectors using a diagram, you draw the vectors 'tip-to-tail' or construct a suitable parallelogram. 2) The correct formula for the cosine law is ##c^2 = a^2 + b^2~–~ 2ab...

The difference between sequences and series is trivial. Are you sure you’ve asked what you intended? But there could be casual misuse of terminology. Typically a student might use the word 'series' when they mean 'sequence'. (A bit like a physics student using 'velocity' when they mean 'speed'.)

The intended original question is probably something like this: Block B (mass ##M##) is initially at rest, in equilibrium, on the slope. The spring (of negligible mass and spring constant ##k##)) is hanging freely. Block A (mass ##m##) is then attached to the lower end of the spring and...

In Posts #5 and #8 I was referring only to the case of a non-oscillating mass(A) in equilibrium. I hope this was clear from what I wrote. I had not realised that the OP was asking about a system with mass A oscillating – that isn't explcitly stated in the question, but I could/should have...

At the point when slipping starts, the tension (##kx##) must be equal to both ##mg## and ##Mg \sin \theta + \mu Mg \cos \theta##. EDIT. Apologies. I have misinterpreted the question. I thought mass A was in equilibrium, but it is performing simple harmonic motion (SHM). So my post is...

I’m not entirely sure what the difficulty is, but this might help... Imagine gradually adding weights to to A, i.e. gradually increasing ##m##. While there is no slipping, the spring’s extension, ##x##, will gradually increase and the spring tension will equal ##mg##. Eventually. ##m## will...

The key is to identify all the forces exerted by the water on the various internal surfaces of the double- piston. Note that the small blue piston (top left) is assumed frictionless: it exerts a force on the water but no force on the double-piston. Name the various surfaces of the...

It has doubled - see the 2 areas indicated in yellow: Minor edit.

If I understand correctly, 's' is the piston's effective surface area. By going from the single-piston to the double-piston, you have doubled this area. You need to take this into account.

Check your working. I get ##T=\frac{-5a+300}{4}##. I don't know if this is the only mistake. As @kuruman says, the preferred approach is to work algebraically and only substitute values at the very end. (Admittedly the algebra isn't very pleasant here!) BTW, here's a general note about using...

You mean "If the acceleration of the cylinder's centre of mass is 0,". With some assumptions, the above equations look ok . (A free body diagram of the cylinder with the forces clearly marked would remove the need for the asumptions!) No. The angular speed of the cylinder gradually...