Answer:
KE = 1.75 J
Explanation:
given,
mass of ball, m₁ = 300 g = 0.3 Kg
mass of ball 2, m₂ = 600 g = 0.6 Kg
length of the rod = 40 cm = 0.4 m
Angular speed = 100 rpm= 
=10.47\ rad/s
now, finding the position of center of mass of the system
r₁ + r₂ = 0.4 m.....(1)
equating momentum about center of mass
m₁r₁ = m₂ r₂
0.3 x r₁ = 0.6 r₂
r₁ = 2 r₂
Putting value in equation 1
2 r₂ + r₂ = 0.4
r₂ = 0.4/3
r₁ = 0.8/3
now, calculation of rotational energy




KE = 1.75 J
the rotational kinetic energy is equal to 1.75 J
Between 1589-1592 when he discovered projecctile motion
Answer:
(a) 40.6 degree
Explanation:
When refraction takes place from slab to water, the critical angle is 60 degree.
Use Snell's law
refractive index of water with respect to slab



μs = 1.536
Now for slab air interface, the critical angle is C.


1 / 1.536 = Sin C
C = 40.6 degree
Let us first know the given: Tennis ball has a mass of 0.003 kg, Soccer ball has a mass of 0.43 kg. Having the same velocity at 16 m/s. First the equation for momentum is P=MV P=Momentum M=Mass V=Velocity. Now let us have the solution for the momentum of tennis ball. Pt=0.003 x 16 m/s= ( kg-m/s ) I use the subscript "t" for tennis. Momentum of Soccer ball Ps= 0.43 x 13m/s = ( km-m/s). If we going to compare the momentum of both balls, the heavier object will surely have a greater momentum because it has a larger mass, unless otherwise the tennis ball with a lesser mass will have a greater velocity to be equal or greater than the momentum of a soccer ball.