How much centripetal force is needed to make a body of mass 0.5kg to move in a circle of radius 50cm with speed 3ms^-1 ?

The de broglie relation λ=h/p can be rewritten in terms of the wave number k as p=kℏ. recall that wave number is defined by k=2π/λ. using the fact that λ=v/f, find the wave numbers k1 and k2 corresponding to frequencies f1 and f2. express your answer as two expressions

Which statement correctly describes the relationship between frequency and wavelength?

What is the average speed of a car that travels 40 mph for 1 hour and 60 mph in another hour?