Answer:
W = 3.73 eV
Explanation:
Given data:
wavelength of photons 240 nm
kinetic energy 1.45 eV
B y using photoelectric equation
Kinetic Energy = Photon Energy - work friction


= 5.179 eV
= 5.18 eV
= (5.18 - 1.45) eV
W = 3.73 eV
Mass of the are is 2100 kg
Answer:
u = 3.35 m/s
Explanation:
given,
mass , m = 0.455 kg
R = 0.675 m
Height of Loop = 1.021 m
the speed required at the top of loop be v
equating the force vertically


v² = 6.622
v = 2.57 m/s
Let the initial speed of ball be u
using conservation of energy

where, 



0.7 u² = 7.85092
u² = 11.2156
u = 3.35 m/s
the initial speed is 3.35 m/s
Answer:
utrasonic
Explanation:
these are sounds beyond our hearing capacity range of 20-20kHz