Answer:
See the answers below.
Explanation:
to solve this problem we must make a free body diagram, with the forces acting on the metal rod.
i)
The center of gravity of the rod is concentrated in half the distance, that is, from the end of the bar to the center there is 40 [cm]. This can be seen in the attached free body diagram.
We have only two equilibrium equations, a summation of forces on the Y-axis equal to zero, and a summation of moments on any point equal to zero.
For the summation of forces we will take the forces upwards as positive and the negative forces downwards.
ΣF = 0

Now we perform a sum of moments equal to zero around the point of attachment of the string with the metal bar. Let's take as a positive the moment of the force that rotates the metal bar counterclockwise.
ii) In the free body diagram we can see that the force acts at 18 [cm] of the string.
ΣM = 0
![(15*9) - (18*W) = 0\\135 = 18*W\\W = 7.5 [N]](https://tex.z-dn.net/?f=%2815%2A9%29%20-%20%2818%2AW%29%20%3D%200%5C%5C135%20%3D%2018%2AW%5C%5CW%20%3D%207.5%20%5BN%5D)
Answer:
The number of turns in secondary coil is 4000
Explanation:
Given:
Current in primary coil
A
Current in secondary coil
A
Number of turns in primary coil 
In case of transformer the relation between current and number of turns is given by,

For finding number of turns in secondary coil,



Therefore, the number of turns in secondary coil is 4000
Answer: The ice cube would float on top of the water and the rock would sink to the bottom.
Explanation: The ice cube has a smaller density than the rock which allows the ice cube to float but makes the rock sink to the bottom of the glass of water.
Answer:
<em>500Joules</em>
Explanation:
Kinetic energy = 1/2mv²
m is the mass of the wood
v is the velocity
Given
Mass = 10kg
Velocity v = 10m/s
Substitute into the formula and get KE
KE = 1/2 * 10 * 10²
KE = 1/2 * 1000
KE = 500Joules
<em>Hence the kinetic energy of the wood during delivery is 500Joules</em>
Answer: To form a cloud, the air that rises must cool to the point where some of the water vapor molecules "clump together" at a faster pace than they are pulled apart by their thermal energy. These molecules then condense to form the clouds and water droplets.