Answer:
A)Qa=80 J
B)Qr= 100 J
Explanation:
Given that
W= 20 J
COP = 4
Heat rejected from cold reservoir = Qa
Heat exhausted to hot reservoir = Qr
The COP of refrigerator is given as
Qa= 4 x 20 J
Qa=80 J
By using first law of refrigerator
Qr= Qa + W
Qr= 80 + 20 J
Qr= 100 J
A)Qa=80 J
B)Qr= 100 J
Answer:
<em>speed of the alpha particle is 2 x 10^7 m/s.</em>
Explanation:
energy of alpha particle = 8.3 Mev
1 Mev = 1.602 x 10^-13 J
8.3 Mev =
solving, = 8.3 x 1.602 x 10^-13 = 1.329 x 10^-12 J
mass of a alpha particle = 6.645 x 10^−27 kg
The energy of the alpha particle is the kinetic energy KE of the alpha particle
KE =
where m is the mass of the alpha particle
v is the velocity of the alpha particle
substituting values, we have
1.329 x 10^-12 =
= 4 x 10^14
= <em>2 x 10^7 m/s</em>
Answer:
A. 98,000 J
Explanation:
The gravitational potential energy of an object is given by
U = mgh
where
m is the mass of the object
g is the gravitational acceleration
h is the heigth above the ground
In this problem,
m = 2000 kg
g = 9.8 m/s^2
h = 5.0 m
Substituting into the equation, we find