Answer:
42.5W
Explanation:
To solve this problem we must go back to the calculations of a weighted average based on the time elapsed thus,

We need to calculate the average power dissipated by the 800\Omega resistor.
Our values are given by:


Aplying the values to the equation we have:



Answer:
Average density of Sun is 1.3927
.
Given:
Radius of Sun = 7.001 ×
km = 7.001 ×
cm
Mass of Sun = 2 ×
kg = 2 ×
g
To find:
Average density of Sun = ?
Formula used:
Density of Sun = 
Solution:
Density of Sun is given by,
Density of Sun = 
Volume of Sun = 
Volume of Sun = ![\frac{4}{3} \times 3.14 \times [7.001 \times 10^{10}]^{3}](https://tex.z-dn.net/?f=%5Cfrac%7B4%7D%7B3%7D%20%5Ctimes%203.14%20%5Ctimes%20%5B7.001%20%5Ctimes%2010%5E%7B10%7D%5D%5E%7B3%7D)
Volume of Sun = 1.436 ×

Density of Sun = 
Density of Sun = 1.3927 
Thus, Average density of Sun is 1.3927
.
Answer:
6926.4J
Explanation:
Given parameters:
Mass of iron = 200g
Initial temperature = 100°C
Final temperature = 22°C
Unknown:
Amount of heat transferred to the water = ?
Solution:
The quantity of heat transferred to the water is a function of mass and temperature of the iron;
H = m c Ф
m is the mass of the iron
Ф is the change in temperature
C is the specific heat capacity of iron = 0.444 J/g°C
Now;
insert the parameters and solve;
H = 200 x 0.444 x (100-22)
H = 6926.4J
Answer:
1) 883 kgm2
2) 532 kgm2
3) 2.99 rad/s
4) 944 J
5) 6.87 m/s2
6) 1.8 rad/s
Explanation:
1)Suppose the spinning platform disk is solid with a uniform distributed mass. Then its moments of inertia is:

If we treat the person as a point mass, then the total moment of inertia of the system about the center of the disk when the person stands on the rim of the disk:

2) Similarly, he total moment of inertia of the system about the center of the disk when the person stands at the final location 2/3 of the way toward the center of the disk (1/3 of the radius from the center):

3) Since there's no external force, we can apply the law of momentum conservation to calculate the angular velocity at R/3 from the center:



4)Kinetic energy before:

Kinetic energy after:

So the change in kinetic energy is: 2374 - 1430 = 944 J
5) 
6) If the person now walks back to the rim of the disk, then his final angular speed would be back to the original, which is 1.8 rad/s due to conservation of angular momentum.
Answer:
T = 3990 N
Explanation:
The free body diagram for the elevator consists of a tension force pointing up, and its weight pointing down. So the elevator's net force is:
F = T - 2940N
ad at the same time, using Newton's second law, we have that this net force should equal the elevator's mass (300 kg) times its acceleration (a):
T - 2940N = 300kg (3.5m/s^2)
then
T = 2940 N + 1050 N
T = 3990 N