The mass of air inside a room of dimension `(3 xx 4 xx 6) m^3` can be compared to the mass of (a) hen (b) pencil (c) table (d) truck. Choose the correct option. [Given density of air = `1.3 kg m-^3]`.

In a test experiment pn a model aeroplane in a wind tunnel, the flow speeds on the upper and lower surfaces of the wing are 70 m s^-1 and 63 m s^-1 respectively. What is the lift on the wing if its area is 2.5 m^2 ? Take the density of air to be 1.3 kg m^-3 .

The maximum value of costheta is a)1 b)2 c)3 d)4

In Millikan’s oil drop experiment, what is the terminal speed of an uncharged drop of radius 2.0 xx 10^-5m and density 1.2 xx 10^3 kg m^-3 ? Take the viscosity of air at the temperature of the experiment to be 1.8 xx 10^-5 Pa s. How much is the viscous force on the drop at that speed? Neglect buoyancy of the drop due to air.

The distance covered by a particle in time t is given by x = a + bt+ct^2+dt^3 , find the dimensions of a,b,c and d.

A and B are two sets such that (A xx B) consists of 6 elements. If three elements-of (Axx B) are (1, 3), (2, 5) and (3, 3), find the remaining elements of (A xx B) .

The measured mass and volume of a body are 22.42 g and 4.7 cm ^3 the possible errors in measuements of mass and volume are respectively 0.01 g and 0.1 cm ^3 The maximum error in density is about

The blades of a windmill sweep out a circle of area A. (a) If the wind flows at a velocity v perpendicular to the circle, what is the mass of the air passing through it in time f?(b) What is the kinetic energy of the air? (c) Assume that the windmill converts 25% of the wind’s energy into electrical energy, and that A = 30 m^- 2 , v = 36 km/h and the density of air is 1.2 kg m^-3 . What is the electrical power produced?