PHYSCI 5 Lecture Notes - Lecture 15: Lipolysis, Insulin, Cortisol

A lever enables you to lift objects that are too heavy to lift byhand. The lever pictured here consists of a long board placed on apivot. To lift the concrete slab on the left end of the board, theperson pushes downward on the right end.

A. Using the concept of torque, explain why a lever makes it easierto lift the heavy slab. Hint: in order for the board to "swing"clockwise, thereby lifting the slab, how must the torque exerted bythe person on the board compare to the torque exerted by the slabon the board?

B. The slab weighs 1000 Newtons. The segment of the board to theright of the pivot is 5 times longer than the segment of the boardto the left of the pivot. Assuming the board is very light, howhard must the person push down on the right end of the board tolift the slab?

C. A student last year gave this explanation for why this leverworks:
"if you take the slab off the board, and if the student lets go ofthe board,the board will naturally swing clockwise; it ends up withits right end on the ground. thats because the weight of the boardto the right of the pivot is greater than the weight of the boardto the left of the pivot. My point is, even with the slab in place,the weight of the board "helps" the student make the board swingclockwise. Thats why the students force on the board can be lessthan the slabs weight"

In what ways do you agree or disagree with this explanation? hint:itll help to check for coherence between your answer here and youranswers to A and B.


PLEASE PLEASE PPLEAASEE HELP ME ANSWER THIS!! I HAVE ABSOLUTELY NOCLUE ON HOW TO START. BUT PLEASE ,IF YOU ANSWER THIS, BE GOOD ATEXPLAINING THOROUGHLY, MY TA WILL SERIOUSLY TAKE POINTS OFF FOR THESLIGHTEST THING. SORRY FOR SUCH LONG QUESTION. :/ THANKS IN ADVANCE

A lever enables you to lift objects that are too heavy to lift byhand. The lever pictured here consists of a long board placed on apivot. To lift the concrete slab on the left end of the board, theperson pushes downward on the right end.

A. Using the concept of torque, explain why a lever makes it easierto lift the heavy slab. Hint: in order for the board to "swing"clockwise, thereby lifting the slab, how must the torque exerted bythe person on the board compare to the torque exerted by the slabon the board?

B. The slab weighs 1000 Newtons. The segment of the board to theright of the pivot is 5 times longer than the segment of the boardto the left of the pivot. Assuming the board is very light, howhard must the person push down on the right end of the board tolift the slab?

C. A student last year gave this explanation for why this leverworks:
"if you take the slab off the board, and if the student lets go ofthe board,the board will naturally swing clockwise; it ends up withits right end on the ground. thats because the weight of the boardto the right of the pivot is greater than the weight of the boardto the left of the pivot. My point is, even with the slab in place,the weight of the board "helps" the student make the board swingclockwise. Thats why the students force on the board can be lessthan the slabs weight"

In what ways do you agree or disagree with this explanation? hint:itll help to check for coherence between your answer here and youranswers to A and B.


PLEASE PLEASE PPLEAASEE HELP ME ANSWER THIS!! I HAVE ABSOLUTELY NOCLUE ON HOW TO START. BUT PLEASE ,IF YOU ANSWER THIS, BE GOOD ATEXPLAINING THOROUGHLY, MY TA WILL SERIOUSLY TAKE POINTS OFF FOR THESLIGHTEST THING. SORRY FOR SUCH LONG QUESTION. :/ THANKS IN ADVANCE