Why doesn't the leaning tower of Pisa topple over?

Statement-1: Moon cannot be used as a satellite for communication. Statement-2: Moon doesn't move in the equatorial plane of the earth.

Infinite numbers of bloks are placed on a table on a edge as shown in the diagram. What is the minimum value of L so that the blocks are just going to topple over the table ?

The discharging current in the atmosphere due to the small conductivity of air is known to be 1800 A on an average over the globe. Why then does the atmosphere not discharge itself completely in due course and become electrically neutral ? In other words, what keeps the atmosphere charged?

Assertion : If Earth doesn't have atmosphere, than there will be very much cold. Reason : In convection, heat transfers through air.

Why can't the efficiency of a heat engine ever be 100 % ?

Why don't we use water instead of mercury in Torricelli experiment? If we are ready to do this experiment, what length of tube is needed?

The speed-time graph of a particle moving along a fixed direction is shown in figure. Obtain the distance traversed by the particle between (a) t =0 s to 10s. (b) t = 2 s to 6s. What is the average speed of the particle over the intervals in (a) and (b) ?

According to Newton's law of gravitation, if each body in the universe attracts every other body, why don't two bodies come towards each other?

Comprehension # 6 A 1 kg block is given a velocity of 15 m//s towards right over a very long rough plank of mass 2 kg as shown in figure. If coeficient of friction between the two blocks is equal to 0.4 , then magnitude of linitial slope of p_(1) versus t and p_(2) versus t (in SI unit) will be :-