Motion — Science STD 9 — Question

Particles P and Q are undergoing uniform horizontal circular motions along concentric circles of different radii in clockwise sense P completes each round in 2min while Q does it is 5min time required by Q to make one revolution around P is.

The frequency of sound waves in water is:

Crystals of KMnO₄ in water proves that:

The best way to recover sugar form an aqueous sugar solution is:

The size of most of the cells is best expressed in:

A homogenous mixture of two solids is:

Palcoid scales are present in:

1. Anabas.
2. Scoliodon.
3. Lizard.
4. Crorodile.

While designing an auditorium, an engineer uses which of the following points?
A: Makes concave back stage:
B: Uses sound absorbing materials.
C: Reduces reverberation time.
D: Increases echo.

A body is projected vertically upward from the ground. Taking vertical upward direction as positive and point of projection as origin, the sign of displacement of the body from the origin when it is at height h during upward and downward journey will be:

If frequency of a wave is 5 Hz, then it is: