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:
E=0.036 V/m
Explanation:
Given that
Resistivity ,ρ=2.44 x 10⁻⁸ ohms.m
d= 0.9 mm
L= 14 cm
I = 940 m A = 0.94 A
We know that electric field E
E= V/L
V= I R
R=ρL/A
So we can say that
E= ρI/A
Now by putting the values
E=0.036 V/m
Answer:
Explanation: 100 watts is a unit of power.
A watt is also the amount of energy being consumed. So the more watts the brighter the light bulb is lit.
When its temperature increases, the reactants have more kinetic energy so the frequency of effective collision increases, resulting in a faster rate of chemical reaction.
(a) 1200 rad/s
The angular acceleration of the rotor is given by:
where we have
is the angular acceleration (negative since the rotor is slowing down)
is the final angular speed
is the initial angular speed
t = 10.0 s is the time interval
Solving for 
, we find the final angular speed after 10.0 s:
(b) 25 s
We can calculate the time needed for the rotor to come to rest, by using again the same formula:
If we re-arrange it for t, we get:
where here we have
is the initial angular speed
is the final angular speed
is the angular acceleration
Solving the equation,
