A construction worker needs to lift a heavy metal beam using a lever but has a limited length of plank. Which adjustment would allow the worker to lift the beam with the least effort if the position of the fulcrum can be changed but the plank length remains constant?
Move the fulcrum closer to the beam
For a first-class lever: Mechanical Advantage (MA) = Effort arm / Load arm.
With the plank length fixed, moving the fulcrum closer to the beam (load) shortens the load arm and lengthens the effort arm, thereby increasing the MA.
A higher MA means the same effort lifts a heavier load — or the same load requires less effort. This is why a crowbar is positioned with its fulcrum as close to the object being pried as possible.
Moving the fulcrum closer to the worker (option 2) would do the opposite: shorten the effort arm, reduce MA, and require more effort.
Which of the following best describes the velocity-time graph for an object moving with uniform velocity?
A construction worker needs to lift a heavy metal beam using a lever but has a limited length of plank. Which adjustment would allow the worker to lift the beam with the least effort if the position of the fulcrum can be changed but the plank length remains constant?
A student pushes a heavy box that is already moving across a rough floor. If the force applied by the student is exactly equal to the frictional force opposing the motion, what will happen to the box?
Which experimental discovery contradicted Thomson's model of the atom and led to its rejection?
Which of the following best describes how sound travels through air?
A factory plans to install a powerful electromagnet for lifting metal scraps. To maximize the magnetic field strength around the coil, which of the following combinations would be most effective?
Which of the following statements best describes the behavior of magnetic field lines around a straight current-carrying conductor?
Which of the following statements best describes the behavior of magnetic field lines around a straight current-carrying conductor?
A student pushes a heavy box that is already moving across a rough floor. If the force applied by the student is exactly equal to the frictional force opposing the motion, what will happen to the box?
A construction worker needs to lift a heavy metal beam using a lever but has a limited length of plank. Which adjustment would allow the worker to lift the beam with the least effort if the position of the fulcrum can be changed but the plank length remains constant?
What special name is given to the frictional force exerted by a fluid?
______ is used in periscope.
Zero degree centigrade is equal to what degree Fahrenheit?
A. 100°F
B. 30°F
C. 34°F
D. 32°F
Keeping voltage constant, if more lamps are put into a series circuit, the overall current in the circuit:
A. Increases
B. Decreases
C. Remains the same
D. Becomes infinite
Excessive curvature of eye lens leads to _______