Why are ruber tyres preffered to iron tyres?

Why is a concave mirror preffered to plane mirror for shaving?

Why are tyres made circular?

Steel si preferred for making permanent magnets, whereas soft iron is prefferred for making electromagnets. Give one reason.

A tyre manufacturing company kept a record of the distance covered before a tyre needed to be replaced. The table shows the results of 1000 cases.If you buy a tyre of this company, what is the probability that : it will need to be replaced before it has covered 4000 km?\

A tyre manufacturing company kept a record of the distance covered before a tyre needed to be replaced. The table shows the results of 1000 cases. If you buy a tyre of this company, what is the probability that : it will need to be replaced after it has covered somewhere between 4000 km and 14000 km?

Define molality and molarity . Why is molality preffered over molarity?

Why determination of osmotic pressure is preffered for finding molecular mass of macro-molecules?