Answer:
(a) v = 3..6 m/s
(b) The rain falling downward has been able to affect the horizontal motion of the car by reducing it's velocity from 4 m/s to 3.6 m/s.
Explanation:
from the question we have the following:
mass of the car (Mc) = 24,000 kg
initial velocity of the car (u) = 4 m/s
mass of water (Mw) = 3000 kg
final velocity of the car (v) = ?
(a) we can calculate the final momentum of the car by applying the conservation of momentum where
initial momentum = final momentum
Mc x U = (Mc + Mw) x V
24000 x 4 = (24000 + 3000) x v
96,000 = 27000v
v =3.6 m/s
(b) The rain falling downward has been able to affect the horizontal motion of the car by reducing it's velocity from 4 m/s to 3.6 m/s.
The weight of the meterstick is:

and this weight is applied at the center of mass of the meterstick, so at x=0.50 m, therefore at a distance

from the pivot.
The torque generated by the weight of the meterstick around the pivot is:

To keep the system in equilibrium, the mass of 0.50 kg must generate an equal torque with opposite direction of rotation, so it must be located at a distance d2 somewhere between x=0 and x=0.40 m. The magnitude of the torque should be the same, 0.20 Nm, and so we have:

from which we find the value of d2:

So, the mass should be put at x=-0.04 m from the pivot, therefore at the x=36 cm mark.
Answer:

Explanation:
According to the newton's second law of motion we can apply F=ma hear
Force = mass * acceleration
(assume the piano is moving left side )
←F = ma

Answer:
2.286 ohm
Explanation:
R1 = 16 ohm
R2 = 8 ohm
R3 = 4 ohm
They all are connected in parallel combination
Let the equivalent resistance is R.
1/R = 1/R1 + 1/R2 + 1/R3
1/R = 1/16 + 1/8 + 1/4
1/R = (1 + 2 + 4) / 16
1/R = 7 / 16
R = 16/7 = 2.286 ohm