Answer:
speed of white ball is 1.13 m/s and speed of black ball is 2.78 m/s
initial kinetic energy = final kinetic energy

Explanation:
Since there is no external force on the system of two balls so here total momentum of two balls initially must be equal to the total momentum of two balls after collision
So we will have
momentum conservation along x direction

now plug in all values in it

so we have

similarly in Y direction we have

now plug in all values in it

so we have


now from 1st equation we have



so speed of white ball is 1.13 m/s and speed of black ball is 2.78 m/s
Also we know that since this is an elastic collision so here kinetic energy is always conserved to
initial kinetic energy = final kinetic energy


Answer:
dimensions of k are kg / s^2
Explanation:
F=ma (Newton's second law)
F=-kx (Hooke's law)
so equate both
-kx = ma
k = -ma/x
= mass * acceleration / distance (dimensions, -1 has no dimension)
= kg * m/s^2 / m
= kg / s^2
Speed is not a vector so horizontal speed does not sighify anything. If u meant velocity it vill be same as the initial velocity in horizontal direction
Answer:
v = 10 m/s
Explanation:
Let's assume the wheel does not slip as it accelerates.
Energy theory is more straightforward than kinematics in my opinion.
Work done on the wheel
W = Fd = 45(12) = 540 J
Some is converted to potential energy
PE = mgh = 4(9.8)12sin30 = 235.2 J
As there is no friction mentioned, the remainder is kinetic energy
KE = 540 - 235.2 = 304.8 J
KE = ½mv² + ½Iω²
ω = v/R
KE = ½mv² + ½I(v/R)² = ½(m + I/R²)v²
v = √(2KE / (m + I/R²))
v = √(2(304.8) / (4 + 0.5/0.5²)) = √101.6
v = 10.07968...
We can solve this using the Law of Conservation of Momentum. If both marbles are in our system, the initial momentum should equal the final momentum.
The initial momentum can be solved for as so:

*

+

=

(0.06)(0.7) + (0.03)(0) = 0.042 [kg * m/s]
So if the system has an initial momentum of 0.042, it should have the same final momentum.

(0.06)(-0.2) + (0.03)(

) = 0.042
(0.03)(

) = 0.54
(

) = 18 [m/s]