If K$$_1$$ and K$$_2$$ are maximum kinetic energies of photoelectrons emitted when lights of wavelengths $$\lambda_1$$ and $$\lambda_2$$, respectively incident on a metallic surface and $$\lambda_1=3\lambda_2$$, then
A car is moving with a speed of 54 km/h. If after 3 s, the driver applies brakes and it stops, then how much distance is covered by the car before coming to rest?
A source of sound emits sound waves at frequency $$f_0$$. It is moving towards an observer with fixed speed $${v_s}$$ ($${v_s},v$$, where $$v$$ is the speed of sound in air.) If the observers were to move towards the source with speed $$v_0$$, one of the following two graphs (A and B) will give the correct variation of the frequency $$f$$ heard by the observer as $$v_0$$ is changed.
The variation of $$f$$ with $$v_0$$ is given correctly by
In which mode of transmission, the heat waves travel along straight line with the speed of light?