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)
The power of the engine is 320 W.
<u>Explanation:</u>
Power may be defined as the rate of doing work (or) work done per unit time. One unit of energy is used to do the one unit of work.
Power = Work done / Time taken
Given, Force = 80 N, height = 5 m , final velocity = 4 m/s
To calculate the power, we must know the time taken.
To find the time, use the distance and speed formula which is given by
Time = Distance / speed
Here distance = 5 m and speed = 4 m/s
Time = 5 / 4 = 1.25 s.
Now, Power = work done / time
= (F * d) / t = (80 * 5) / 1.25
Power = 320 W.
The standard unit of power is watt (W) which is joule per second.
Pretty sure it’s false....................
Given that, A basesball is dropped from 100 meters above the surface of the earth. If the same baseball was dropped from 100 meters above the surface of the moon, it will take more time to hit the ground as compare to the ball dropped on earth. This is moon's gravity is one-sixth of that of earth. Object falling on earth possess more force of attraction. So it will reach the earth in lesser time. At moon the force of attraction is low compare to that of earth. Object will take more time to reach the surface.
