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ApPhysicsStudent
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14). Student A lifts a 50-N box from the floor straight up to a height of 40 cm in 2 s. Student B lifts a 40 N boxes straight up from the floor to a height of 50 cm in 1 s. Compared to Student A, Student B does
(A) The same work but develops more power.
(B) The same work but develops less power.
(C) More work but develops less power.
(D) Less work but develops more power.15). Now Student A instead lifts the 50 N box from the floor diagonally, moving the box 40 cm to the right and 40 cm upward in the same 2 s.
(A) Compared to the work he did originally, does Student A do more, less or the same work?
(B) Compared to the power he developed originally, does Student A develop more, less or the same power?
Ok, so I know that on #14 the answer is A, same work through the formula F*D=W.
However, our physics teacher claims that on #15 that the answer is Same work and power. She says its based on the equation M*G*H=W because there is no change in KE. I understand what she is talking about.
But, the way I see it is, you should use the equation F*D*CosX=W. X is theta, which you find by the angle between the direction of the force and the direction of the object; in this case it is 0. So then F*D=W. With Pythagorean Theorem, you find that D=56.56 and Force is given at 50N, for a total of 28.28J and 14.14W.
Which one is correct and why is the other not?
(A) The same work but develops more power.
(B) The same work but develops less power.
(C) More work but develops less power.
(D) Less work but develops more power.15). Now Student A instead lifts the 50 N box from the floor diagonally, moving the box 40 cm to the right and 40 cm upward in the same 2 s.
(A) Compared to the work he did originally, does Student A do more, less or the same work?
(B) Compared to the power he developed originally, does Student A develop more, less or the same power?
Ok, so I know that on #14 the answer is A, same work through the formula F*D=W.
However, our physics teacher claims that on #15 that the answer is Same work and power. She says its based on the equation M*G*H=W because there is no change in KE. I understand what she is talking about.
But, the way I see it is, you should use the equation F*D*CosX=W. X is theta, which you find by the angle between the direction of the force and the direction of the object; in this case it is 0. So then F*D=W. With Pythagorean Theorem, you find that D=56.56 and Force is given at 50N, for a total of 28.28J and 14.14W.
Which one is correct and why is the other not?