A whistle is revolved with high speed in a horizontal circle of radius R. to an observer at the centre of the circle the frequency of the whistle will appear to be:
The spectrum of a star’s light is measured and the wavelength of one of the lines as thesodium’s line is found
to be 589 nm. The same line has the wavelength of 497 nm whenobserved in the laboratory. This means the
star is
A bullet of mass 10 g hits a target and penetrates 2 cm into it.If the average friction offered by the target is 100 N,then the velocity with which the bullet hits the target is
Five equal forces of 10N each are applied at one point and all are lying in one plane.If the angles between them are equal,the resultant force will be:
Two point charge +3μC and +8μC repel each other with a force of 40 N if a charge of -5μC us added to each of them then the force between them will become
A listener observes the frequency “f” of stationary source. If it move toward with 3
times of velocity of sound. Then the apparent frequency of the sound will be
A particle is moving along a circular path of radius 5 m with uniform speed 5 m/sec what will be the magnitude of centripetal acceleration when the particle completes half revolution
