Sound — Science STD 9 — Question

Which of the following statements are true for pure substances?

1. Pure substances contain only one kind of particles.
2. Pure substances may be compounds or mixtures.
3. Pure substances have the same composition throughout.
4. Pure substances can be exemplified by all elements other than nickel.

1. (i) and (ii)
2. (i) and (iii)
3. (iii) and (iv)
4. (ii) and (iii)

Sound waves produce echo due to:

Pure iodine can be obtained by the process of ______________?

Naphthalene can be separated for sand:

1. By sublimation.
2. By distillation.
3. By crystallisation.
4. By using water as solvent.

A ship of mass 3 × 10⁷kg initially at rest is pulled by a force of 5 × 10⁴N through a distance of 3m. Assume that the resistance due to water is negligible, the speed of the attractive force ship is.

Rutherford’s ‘alpha (α) particles scattering experiment’ resulted in to discovery of:

A body is thrown vertically upward with velocity u, the greatest height h to which it will rise is,

(1) In uniform circular motion, tangential acceleration is zero (2)In uniform circular motion, velocity is constant.

Which of the following statements about Rutherford's model of an atom are correct?