Answer:
Three machines that humans have created are the lever, the wheel, and the axle, and also a pulley. even though there's actually more. A lever is A rigid bar that is free to move around a fixed point, such as a screwdriver. The wheel and axle, everyone should know what that is and what it does, it lifts heavy objects, moves people quickly, and moves parts of a complex machine. Pulleys are used to lift things, pulleys can be used singly or with many pulleys working together in order to transport people or things. They can also be used to provide power from one shaft to another. ... Construction pulleys are used in order to lift and place heavy materials.
Answer:
Explanation:
1.2(0) + 3(0.8) + 1.4(0.8/2) / (1.2 + 3 + 1.4) = 0.5285714... ≈ 0.53 m
Answer:
Part a)

Part b)

Explanation:
Since the ball and rod is an isolated system and there is no external force on it so by momentum conservation we will have

here we also use angular momentum conservation
so we have

also we know that the collision is elastic collision so we have

so we have

also we know

also we know

so we have


now we have


Part b)
Now we know that speed of the ball after collision is given as

so it is given as
