It could never actually happen like this, but the question is
looking for you to 'conserve' the momentum.
Momentum of a moving object is (mass) x (velocity).
Like velocity, momentum has a direction.
Momentum is one of those things that's 'conserved'.
That means that momentum can't appear out of nowhere, and
it doesn't disappear. The total after the collision is the same as
the total was before the collision.
Momentum of the skinny player:
(70 kg) x (3 m/s north) = 210 kg-m/s north.
Momentum of the heavy player:
(80 kg) x (1.5 m/s south) = 120 kg-m/s south .
Total momentum before the collision is
(210 kg-m/s north) + (120 kg-m/s south)
= 90 kg-m/s north .
It has to be the same after the collision.
(mass) x (velocity) = 90 kg-m/s north.
The mass after the collision is 150 kg, because they get
tangled up and stuck together, and they move together.
(150 kg) x (velocity) = 90 kg-m/s north .
Divide each side
by 150 kg : velocity = (90 kg-m/s north) / (150 kg)
= (90/150) (kg-m/s / kg north)
= 0.6 m/s north .
initial acceleration of rocket is given as
a = 12 m/s^2
h = 26 m
now we can use kinematics to find its speed
now after this it will be under free fall
so now again using kinematics
at maximum height
total height from the ground = 31.8 + 26 = 57.8 m
Part b)
now after reaching highest height it will fall to ground
So in order to find the speed we can use kinematics again
Part c)
first rocket accelerate to reach height 26 meter and speed becomes 24.98 m/s
now we have
after this it will reach to highest point and final speed becomes zero
now from this it will fall back to ground and reach to final speed 33.67 m/s
now we have
so total time is given as
<em>t = 3.44 + 2.55 + 2.1 = 8.1 s</em>
Answer:
(a) 0.33 second
(b) 6 cm/s
Explanation:
Frequency, f = 3 waves per second
wavelength, λ = 2 cm = 0.02 m
(a) The period of wave is defined as the time taken by the wave to complete one oscillation. It is the reciprocal of frequency.
T = 1 / f = 1 / 3 = 0.33 second
(b) the relation between wave velocity, frequency and wavelength is given by
v = f x λ
v = 3 x 0.02 = 0.06 m /s
v = 6 cm /s
The net force acting on the object perpendicular to the table is
∑ F[perp] = F[normal] - mg = 0
where mg is the weight of the object. Then
F[normal] = mg = (15 kg) (9.8 m/s²) = 147 N
The maximum magnitude of static friction is then
0.40 F[normal] = 58.8 N
which means the applied 40 N force is not enough to make the object start to move. So the object has zero acceleration and does not move.
