Given:
Mass of the rail road car, m = 2 kg
velocity of the three cars coupled system, v' = 1.20 m/s
velocity of first car, 
= 3 m/s
Solution:
a) Momentum of a body of mass 'm' and velocity 'v' is given by:
p = mv
Now for the coupled system according to law of conservation of momentum, total momentum of a system before and after collision remain conserved:
(1)
where,
= velocity of the first car
= velocity of the 2 coupled cars after collision
Now, from eqn (1)
v' = 1.80 m/s
Therefore, the velocity of the combined car system after collision is 1.80 m/s
Answer:
Option A
The apparent change in frequency of waves due to the motion of a source
Explanation:
Doppler effect is the apparent change in frequency of waves due to the motion of a source. Doppler effect occurs when the source of waves moves towards the observer which causes emission of successive wave crests to be closer to the observer compared to the previous wave crest. This phenomenon was named after Austrian Physicist called Christian Doppler
Answer:
Explanation:
Since, as we know, the potential difference 'ΔV' is the difference of between the Potential energy per unit charge U/qo at one point 'B' to Potential energy per unit charge at other point 'A'. It so happens when a test charge 'qo' moves from point A to B, the potential difference becomes the change of potential energy of the system, i.e.
Answer:
Maximum weight that can be lifted = 18,000 N
Explanation:
Given:
Cross-sectional area of input (A1) = 0.004 m²
Cross-sectional area of the output (A2) = 1.2 m
²
Force (F) = 60 N
Computation:
Pressure on input piston (P1) = F / A1
Assume,
Maximum weight lifted by piston = W
Pressure on output piston (P2) = W / A2
We, know that
P1 = P2
[F / A1] = [W / A2]
[60 / 0.004] = [W / 1.2]
150,00 = W / 1.2
Weight = 18,000 N
Maximum weight that can be lifted = 18,000 N
