Mention some of the time intervals of importance in physics.

What is physics?

What are alloys? Name an important alloy which contains some of the lanthanoid metals. Mention its uses.

Explain clearly, with examples, the distinction between :- magnitude of average velocity over an interval of time, and the average speed over the same interval. [Average speed of a particle over an interval of time is defined as the total path length divided by the time interval]. Show in both (a) and (b) that the second quantity is either greater than or equal to the first. When is the equality sign true ? [For simplicity, consider one-dimensional motion only].

In the figure gives a speed-time graph of a particle in motion along a constant direction. Three equal intervals of time are shwon. In which interval is the average acceleration greatest in magnitude ? In which interval is the average speed greatest ? Choosing the positive direction as the constant direction of motion, give the signs of v and a in the three intervals. What are the acceleration at the points A,B,C and D?

The time scale studied in physics ranges in

Mention some modified roots and stems which we eat.