Question

Two farmers are trying to move a large rock that sits in a field. They use a long stick as a lever and a brick as the fulcrum, as shown in the diagram. They apply a force on the stick at the location shown by the arrow. However, the rock does not move.
Which change would BEST allow the farmers to move the rock?
A) Moving the brick closer to the rock.
B) Moving the brick to the other side of the rock.
C) Applying a smaller force at the same location on the stick.
D) Applying an equal force at a location farther away from the rock.

Answer 1

D is the answer for usatestprep

Answer 2

Answer:

D) Applying an equal force at a location farther away from the rock.

Explanation:

Here big stone is moved by applying the technique of torque

Here the applied force on the rod will give torque due to which we will have

$\tau = \vec r \times \vec F$

so it is product of force and its distance from fulcrum

So if the the product will be more then we will have more torque in output and that will easily shift the heavy rock

So here the torque can be increased by increasing the product of force and its distance from fulcrum

So here correct answer will be

D) Applying an equal force at a location farther away from the rock.