Comment Critically on the following claims:
(a) an object allways accelerates in the direction of the net force
(b)A lower net force is needed to accelerate an object from rest to 10m/s than is required to accelerate it from rest to 20m/s irrespective of the time take.
Best answer gets 10 Points!!!
2006-11-27 16:43:15 · 6 answers · asked by Brody 3 in Science & Mathematics ➔ Physics
a)For rigid body, center of mass accelerates in the direction of applied external forces. Just Newton's second law and therefore true.
b)As in Newton's second law F=ma, force is dependent on acceleration and not directly to velocity only. So, there is explicit time dependence. hence, it really matters how fast the object gets to 10m/s or 20m/s velocity starting from rest. Therefore this statement is inconclusive with unknow time.
2006-11-27 17:03:09 · answer #1 · answered by observer 3 · 0⤊ 0⤋
a) This statement is FALSE. If the object has infinite mass, then the acceleration would be zero, and therefore would not be in the direction of the net force. Since the statement has to satisy all circumstances to be true, it is false.
b) This statement is FALSE, since the word "needed" appears in it. A much higher force could be applied to accelerate an object from rest to 10m/s than to accelerate it from rest to 20m/s, it would simply take a much shorter time, however since time is not a consideration, the statement is false.
On the other hand, if we were considering the amount of WORK done, then less WORK is done to accelerate an object from rest to 10m/s than to accelerate it from rest to 20m/s, regardless of the time taken.
2006-11-27 18:19:53 · answer #2 · answered by Mez 6 · 0⤊ 0⤋
a)Since (net F) = m*a is a vector equation with net F and a being vectors and m being scalar the 1 st condition holds true.
b) (net F)= m*a and v=at therefore (net F) =mv/t or Ft= mv.
As u see this equation involves time. Hence if one must acclerate a body to 10m/s in say 1 second and to 20m/s in 2 seconds then force required are the same. In case we have 5 seconds to accelerate the body then this case requires even lesser force than the former.
2006-11-27 17:09:29 · answer #3 · answered by Anonymous · 0⤊ 0⤋
I artwork in something that would want to probably change right into a quantum pc. At this second, that is all at a study element; no longer constructive no matter if or not they're going to change into operational each and every time quickly.
2016-10-07 21:45:16 · answer #4 · answered by ? 4 · 0⤊ 0⤋
a) Yes since F= m a and m is something like 1,2,3.. force and acceleration are always in the same direction
b) using a) yes
2006-11-27 16:47:15 · answer #5 · answered by come2turkey:) 2 · 0⤊ 0⤋
I don't see what is challenging about this. Both your statements seem sound and correct.
2006-11-27 16:48:22 · answer #6 · answered by Anonymous · 0⤊ 0⤋