Answer:
Option C: Third Class
Explanation:
This is third class because the effort or the input force is in the middle between the fulcrum and the load.
Explanation:
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: Dry friction is a force that opposes the relative lateral motion of two solid surfaces in
The only three countries who do not use the metric system as their primary system of measurement are the United States, Liberia and Burma (Myanmar).
Other countries have adopted the system but do not use it in all cases, for example road distances and speeds are still measured in miles and miles per hour in the United Kingdom.
<span><span>Velocity is a vector, and the initial and final ones are in opposite directions.
There must have been acceleration in order to change the direction of motion.</span>
A) No. The initial and final velocities are the same.
This is all wrong, and not the correct choice.
It's "Yes", and the initial and final velocities are NOT the same.
B) Yes. The ball had to slow down in order to change direction.
This is poor, and not the correct choice.
The "Yes" is correct, but the explanation is bad.
Acceleration does NOT require any change in speed.
C) No. Acceleration is the change in velocity. The ball's velocity is constant.
This is all wrong, and not the correct choice.
It's "Yes", there IS acceleration, and the ball's velocity is NOT constant.
D) Yes. Even though the initial and final velocities are the same, there is a change in direction for the ball.
This choice is misleading too.
The "Yes" is correct ... there IS acceleration.
The change in direction is the reason.
The initial and final velocities are NOT the same. Only the speeds are.
</span>
A single pulley changes the direction of the effort, but it has
no mechanical advantage. The output force is the same as
the input force, so we'd say that the mechanical advantage is 1.
If there are two pulleys, with the rope going up and down and
around between them several times on its way from the effort
to the load, an arrangement that I think is called 'block and tackle',
then the mechanical advantage turns out to be the number of
strands of rope that are supporting the load.
