Answer: b the energy of light...
Explanation:
Answer:
17280 J or 17.28 kJ
Explanation:
Given that the voltage drop,
U = U2 - U1
U = 9 - 6
U = 3V
Also, we're told that the current, I is equal to 20 mA with the discharge time, t being 80 hrs.
Converting the time from h oi urs to seconds, we have
t = 80 * 3600
t = 288000
Now, to find the energy needed, we're going to use the formula
w = pt, where p = U * I
p = 3 * 20*10^-3
p = 60*10^-3
w = 60*10^-3 * 288000
w = 17280 J or 17.28 kJ
Therefore, the total energy the battery delivers in the 80 hrs is 17.28 kJ
Answer:
a. 0.01 C
b. dissipated to outside environment
Explanation:
Let the specific heat of copper be 0.3846 kJ/kg-K or 384.6 J/kg-C
(a)The original kinetic energy of the block is:

As 85% of this kinetic energy is converted to block internal heat energy, with specific heat we can calculate the rise in temperature:




(b) the remaining 15% energy would probably be dissipated to outside environment as heat energy
Answer:
123.48J
Explanation:
Given parameters:
Mass of the ball = 2.8kg
Height = 4.5m
Unknown:
Potential energy = ?
Solution:
The potential energy is the energy due to the position of a body. It is mathematically given as;
P.E = mgh
m is the mass
g is the acceleration due to gravity
h is the height
Now insert the parameters and solve;
P.E = 2.8 x 4.5 x 9.8 = 123.48J
Your answer would be 4.0 hz.