A bus starts from rest and moves in constant acceleration 2 m/s². calculate it's time of travel if its final velocity is 20m/s.​

10 s

Explanation:

u  =  0 m/s

v  =  20 m/s                          

a  =  2 m/s²                          

t   =  ?                                

                                  a  =    

                                  2  = (20 - 0)/ t

                                  t   =  10 s

J

Explanation:

The complete statement is given as

What is the maximum kinetic energy of electrons ejected from barium (Wo = 2.48 eV) when illuminated by white light, 400 nm to 750 nm ?

= wavelength of the white light = 400 nm = 400 x 10⁻⁹ m

= speed of white light = 3 x 10⁸ ms⁻¹

Energy of the white light is given as

= Work function of barium = 2.48 eV = 2.48 x 1.6 x 10⁻¹⁹ J

= Maximum kinetic energy

Using photoelectric equation we have