The drift speed is defined as `v_(d)=(Delta l//Delta t)`where `(Delta l)`is the distance drifted in a long time `(Delta t)`.Why don't we define the drift speed as the limit of `(Delta l//Delta t)`as (Delta t (rarr)0)?

What type of motion is represented by equation Delta s= v Delta t ?

Let 'l' is the length of median from the vertex A to the side BC of a Delta ABC . Then

A quantity X is given by in_(0) L(DeltaV)/(Delta t) , where in_(0) is the permittivity of free space, L is a length, DeltaV is a potential difference and Delta t is a time interval. The dimensional formula for X is the same as that of -

An element Delta l= Delta x hat i is placed at origin and carries a current I=10A. IF Delta x=1cm magnetic field at point P is….. T.

(a) In the formula X=3YZ^(2) , X and Z have dimensions of capcitnce and magnetic inlduction, respectively. What are the dimensions of Y in MKSQ system? (b) A qunatity X is given by epsilon_(0) L ((Delta)V)/((Delta)r) , where epsilon_(0) is the permittivity of free space, L is a lenght, DeltaV is a potential difference and Deltat is a time interval. Find the dimensions of X . (c) If E,M,J and G denote energy , mass , angular momentum and gravitational constant, respectively. find dimensons of (E J^(2))/(M^(5) G^(2)) (d) If e,h,c and epsilon_(0) are electronic charge, Planck 's constant speed of light and permittivity of free space. Find the dimensions of (e^(2))/(2epsilon_(0)hc) .

A particle is projected with a speed v and an angle theta to the horizontal. After a time t, the magnitude of the instantaneous velocity is equal to the magnitude of the average velocity from 0 to t. Find t.

If a variable line in two adjacent positions has direction cosines l, m, n and I + delta I, m + delta m, n + delta n, then show that the small angle delta theta between the two positions is given by delta theta^2=deltal^2+deltam^2+deltan^2 .

A rocket accelerates straight up by ejecting gas downwards . In small time interval Deltat , it ejects a gas of mass Deltam at a relative speed u . Calculate kE of the entire system at t+Deltat and t and show that the device that ejects gas does work = (1/2) Delta"mu"^(2) in this time interval (negative gravity ).