Answer:
The electric force between them if the pieces of grain are 2 cm apart is
.
Explanation:
Given:
Charge on one grain, 
Charge on another grain, 
Separation between them, 
Electric force acting between two charges
separated by a distance
is given as:

Where,
is Coulomb's constant equal to
.
Now, plug in all the values and solve for
.

Therefore, the electric force between them if the pieces of grain are 2 cm apart is
.
Answer:
The value of 2.2 radians in degree is 126.11°.
Explanation:
Given that,
Angle = 2.2 radians
We need to calculate the value in degrees
We know that,



Hence, The value of 2.2 radians in degree is 126.11°.
Answer:
e_12=1-Tc/Th
This is same as the original Carnot engine.
Explanation:
For original Carnot engine, its efficiency is given by
e = 1-Tc/Th
For the composite engine, its efficiency is given by
e_12=(W_1+W_2)/Q_H1
where Q_H1 is the heat input to the first engine, W_1 s the work done by the first engine and W_2 is the work done by the second engine.
But the work done can be written as
W= Q_H + Q_C with Q_H as the heat input and Q_C as the heat emitted to the cold reservoir. So.
e_12=(Q_H1+Q_C1+Q_H2+Q_C2)/Q_H1
But Q_H2 = -Q_C1 so the second and third terms in the numerator cancel
each other.
e_12=1+Q_C2/Q_H1
but, Q_C2/Q_H2= -T_C/T'
⇒ Q_C2 = -Q_H2(T_C/T')
= Q_C1(T_C/T')
(T1 is the intermediate temperature)
But, Q_C1 = -Q_H1(T'/T_H)
so, Q_C2 = -Q_H1(T'/T_H)(T_C/T') = Q_H1(T_C/T_H) So the efficiency of the composite engine is given by
e_12=1-Tc/Th
This is same as the original Carnot engine.
Answer:
the distance of the top of the window below the windowsill from which the flowerpot fell is 0.31 m
Explanation:
given information:
time, t = 0.420 s
height, h = 1.9 m
the the vertical motion equation:
h =
t + 
where
h = height (m)
= initial velocity (m/s)
t = time (s)
g = gravitational force (9.8
)
first we calculate the velocity of the flowers pot when it reaches top window
h =
t + 
1.9 =
(0.42) + (
)
= (1.9 - (
))/0.42
= 2.47 m/s
now we can find the distance of the windowsil
+ 2gh
v = 0, thus
2gh = - 
h = -
/2g
=
/ (2 x 9.8)
= 0.31 m