Recent content by PeterO

Agreed, but so many diagram are poorly drawn How many times are angles are all drawn as 45 degrees with other sizes marked on them. Of course the sensible student re-draws their own "reasonable" diagram.

The length of the cable is 50cm, the radius of the disk is 30 cm. Why do the setters of such questions provide such hopelessly out of scale diagrams?

Well done, you have successfully explained why the glass slides without reference to, nor need for a centrifugal force - so the original question which began "If centrifugal Force doesn't exist ..." becomes redundant.

The presenter made a very misleading statement. He said the force of gravity had to be slightly more than the normal (reaction) force. The size of the force of gravity is determined by the mass of the two objects (Earth and Person) and the separation of their centres of mass. We cannot alter...

When an object is placed on a horizontal bench in the class room, we have several pairs of forces, which are reaction forces as mentioned in Newtons 3rd law. 1: The object pushes down on the surface -- the surface pushes up on the object. 2: The Earth pulls down on the object -- the object pulls...

You are asking the wrong question!! When you open a fridge drawer, each part of the door moves in a circular path (due to the combined effect of the hinges and your action on the handle) Why doesn't a glass of water on a shelf also follow the circular path that will make it retain its position...

The way I would consider it would be to imagine if the Friction Force was NOT big enough, so the block slips (accelerates) down the slope. The Normal Reaction Force is still the same size (and direction of course - perpendicular to the surface) I would thus always consider the Normal Reaction...

Perhaps you could consider the following reverse experiment. Place an empty beaker on a block of wood, placed on a surface, and establish the static friction. Now progressively add some water to the beaker, and note the increased friction that results. Would your thoughts on what was happening...

The rough water provides a series of crests which will include a section that reflects the light in the appropriate direction that is why the reflected light is so spread out. That bright area you have the red arrow pointing to is just the spread reflection of the bright section on the roof of...

Be careful, that bulge the centre circle might not be what you expected, or were looking for, but if you want P1, P2, P3 and P4 evenly spaced along a semi-circle, and you also want the transition from the initial incidence to the first curve, the first curve to the second curve, the second...

Sorry to come in so late BUT., It looks like the incoming path is meeting the circle (at P1) along a normal (perpendicular to the tangent). Is that true, and is that also true for P2 , P3 and P4? If that is true, the centre of each blue arc is at the intersection of tangents drawn at P1 & P2, P2...

For noticing a change in g, yes, but to find the actual value you would have to be able to precisely measure the length of the pendulum!.

The friction is static, because the tyres are not slipping on the surface - the brakes are not locked on, the wheels are not spinning under attempted acceleration and the tyres are not slipping across the surface, but rolling in a direction along their circumference The friction suddenly...

When someone asks me "How much do you weigh?", I am tempted to say "I weigh the same as a 105kg mass", but instead I give the short answer they are expecting - namely "I weigh 105 kilograms" They already know that means "I weigh as much as a 105 kg mass". btw: in this country 1 lb is also a...

If you used a Golf Cart to study the concept, think as follows. If you removed on the the wheels from the cart, with its stub axle, you could push it along parallel to the tyre, and it would roll easily. If you arranged the tyre to be sideways to motion, you could push and achieve very little...