Distance of 5th dark fringe from centre is $$4 \mathrm{~mm}$$. If $$D=2 \mathrm{~m}, \lambda=600 \mathrm{~nm}$$, then distance between slits is
A sphere pure rolls on a rough inclined plane with initial velocity 2.8 m/s. Find the maximum distance on the inclined plane.
Find gravitational field at a distance of $$2000 \mathrm{~km}$$ from the centre of earth. (Given $$R_{\text {earth }}=6400 \mathrm{~km}, r=2000 \mathrm{~km} \text {, } M_{\text {earth }}=6 \times 10^{24} \mathrm{~kg} \text { ) }$$
Two sources of sound S$$_1$$ and S$$_2$$ are moving towards and away from a stationary observer with the same speed respectively. Observer detects 3 beats per second. Find speed of sources (approximately).
Given, $$f_1=f_2=500$$ Hz, speed of sound in air = 330 m/s