I'm trying to do a problem and problem says asks me what the MINIMUM inital speed necessary to get the rock across the canyon was. It gave us a hint and said that it didn't give us an angle because it implied it in the word: MINIMUM.
What?
Does it mean 0 ?
2006-11-07 12:33:08 · 4 answers · asked by beast 1 in Science & Mathematics ➔ Physics
I believe it means 45 deg, assuming the level of the ground on both sides of the canyon is the same. Anything less than 45 deg and the rock will need to be thrown harder with a flatter trajectory, anything more than 45 deg and it will need to be thrown harder to overcome the force of gravity. A projectile thrown at 45 deg at a specific velocity will reach the furthest horizontal distance.
2006-11-07 12:45:43 · answer #1 · answered by Mez 6 · 0⤊ 0⤋
The energy needed to move the rock is the energy to overcome inertia and friction. If you apply exactly this energy then the rock could move. The rock isn't moving, so its speed is 0, but with the application of even the smallest amount of energy (in the direction of the energy applied to overcome inertia and friction) the rock will move.
We assume the angle that you are moving the rock in is zero so we can ignore the effects of gravity. If the angle is ever so slightly raised then the rock cannot move. If the angle is ever so slightly decreased then the power of gravity comes into play and it will move the rock. Of course the speed of the rock could be 0.0001 feet/sec, or much less. You can decrease this added energy again and again and the rock will move slower and slower; another words you can take the speed of the rock down to zero. It approaches zero, but never quite reaches it. However in it's approach to zero it gets so close that you can consider it to be zero.
If you were to graph the function then your lines would approach the corresponding axis but never quite reach it. You would have a speed of almost zero with a angle of almost zero; or close enough. In calculus this is called a limit. Just like the speed of light a limit cannot be reached, you can only get very close. With a limit of zero then the speed is so slightly above zero that it can be considered to be zero.
2006-11-07 20:54:37 · answer #2 · answered by Dan S 7 · 0⤊ 0⤋
the question can be answered using POTENTIAL and KINETIC ENERGY formulas... that is why the word minimum gives the clue... they expect you to calculate the initial speed so the rock gets to the other side with speed=0
2006-11-07 20:37:13 · answer #3 · answered by Alexwonder 1 · 0⤊ 0⤋
YES DUDE.
I THINK THE ANGLE MAY BE 0
SO THAT IS THE DISPLACEMENT THAT U R CALCULATING.....
HOPE THIS HELPS
BUT I AM NOT SURE............
2006-11-07 20:38:06 · answer #4 · answered by Anonymous · 0⤊ 0⤋