Answer:
v = 10 m/s
Explanation:
recall that velocity is related to wavelength and frequency by the formula
v = fλ
where v = velocity, f = frequency and λ= wavelength
Simply substitute these into the formula:
v = fλ
v = (0.5)(20)
v = 10 m/s
Mechanical energy = potential energy + kinetic energy
The ball is on the ground so it has no potential energy. that's all i know.
Answer:
P = 7.28 N.s
Explanation:
given,
initial momentum of cue ball in x- direction,P₁ = 9 N.s
momentum of nine ball in x- direction, P₂ = 2 N.s
momentum in perpendicular direction i.e. y - direction,P'₂ = 2 N.s
momentum of the cue after collision = ?
using conservation of momentum
in x- direction
P₁ + p = x + P₂
p is the initial momentum of the nine balls which is equal to zero.
9 + 0 = x + 2
x = 7 N.s
momentum in x-direction.
equating along y-direction
P'₁ + p = y + P'₂
0 + 0 = y + 2
y = -2 N.s
the momentum of the cue ball after collision is equal to resultant of the momentum .


P = 7.28 N.s
the momentum of the cue ball after collision is equal to P = 7.28 N.s

Since initial velocity is zero hence , u = 0
=> d = 1/2 * a * t2

on solving we get
d = 86.436 metres
Note ; Here Gravitational Acceleration is take as , g = 9.8 m/s2