Question

Two blocks(block B is heavier than block A) are at rest side by side at the bottom of a frictionless inclined plane. Sometime after block A is kicked up the plane, block B is given a kick up the plane. Block A is headed downplane when it passes block B headed up the plane. At the instance when block A passes block B, ___
a. it has the same position and acceleration as block B
b. it has the same displacement and velocity as block B
c. it has the same position and velocity as block B
d. it has the same velocity and acceleration as block B
e. it has the same position, displacement and veloc

Answer 1

Welcome to OpenStudy. What do you think? Imagine 2 cars; one overtaking the other.

Answer 2

Hmm maybe that wouldn't help so much. Imagine 2 cars passing each other then.

Answer 3

Imagine 2 cars tossed up in the air one after the other.....:)

Answer 4

Haha I actually imagined that.

Answer 5

what say? ... once kicked , their accleration would be the same ,,ie component of earths gravitational acceleration downwards (gsin(theta)) ,, theta is angle made by the plane with the ground

Answer 6

Well one is going down and one is going up when they pass each other. So the one going up will not have the same acceleration as gravity, no?

Answer 7

I think acceleration is from gravity and both will be negative

Answer 8

Depending which way you take is positive, they will have the same sign because the pull is downward. But I was never sure about the magnitude being the same. I'll stop here before I lead this the wrong way. Anyone?

Answer 9

even if they move up , or down ,,,, the only force acting on them in gravitational ,so their only acceleration is gravitaional ,gsin(theta)

Answer 10

and their velocities are also equal....but opposite i guess

Answer 11

Ah then the speed will be the same but velocities different. I thought speed would be the same if both are going the same direction. Since B can move slow and A fast and they still pass each other.

Answer 12

, thats right

Answer 13

I was thinking displacement will be the same if we take the starting point as the initial point. Not position though because they are side by side and not on top of each other.

Answer 14

no,,,as velocities cant be same but speed can be same....in the same way displacements cannot be same while the position vector can be the same,,,,its all because they are equal in magnitude and opposite in direction

Answer 15

here displacement would be the "instantaneous displacement " upwards for one block , down wards for another

Answer 16

Speed can be same, yes but not necessarily in this case as I said earlier. Displacement can be the same if as I said we take the initial point the bottom of the inclined plane. Since displacement will only be the distance between that point and wherever the blocks are(instantaneous displacement)

Answer 17

@rogue0314
The blocks didn't collide, right??

Answer 18

It says "passes" so I would assume no.

Answer 19

seems not because they are side by side

Answer 20

And what do you mean by the term "position" ??

Answer 21

I imagine the coordinate system and a position is a point.

Answer 22

^^ I mean - did the blocks had the same position prior to 'kicking" ??

Answer 23

The way I've been seeing it, no, since there are 2 positions- at A and at B. It's like 2 points side-by-side on the x-axis and we kick them along y-axis.

Answer 24

so is it safe to eliminate choice a and b?

Answer 25

@wolfe8 i think u are confusing "displacement "with "position vector"

Answer 26

NOpe, a) is supposed to be the answer... i feel

Answer 27

By @wolfe8 definition of position; I'll be needing another option - None of These :P

Answer 28

Maybe. I was thinking displacement and acceleration would be the same, but there isn't that answer choice. I know we can cancel out velocity though.

Answer 29

cancelling velocity takes care of b thru e, i will take a, then how doe sone close and select the best answer in here

Answer 30

On the top right to each reply is the 'Best response' button. And on the top left of your window you should see 'Close'