Question

A small cart is rolling down an inclined track and accelerating. It fires a ball perpendicular to the inclined track as it moves. The origin of the reference frame is located at the spot from where the ball is shot out. The x-axis of the reference frame points downward along the inclined track. The y-axis of the reference frame points upward perpendicular to the inclined track.

The angle of the incline is 30°. When the ball is shot out with a 6m/s velocity perpendicular to the inclined track, the cart is moving at 5m/s along the inclined track. Please round your answers to 2 decimal pla

Answer 1

a) Where is the ball located one second after it is shot out ?

Answer 2

This problem seems so easy and i think i am doing all the steps correctly. But, i get the answer wrong every time. I don' t know whats wrong.

Answer 3

@myname

Answer 4

are you asked for the coordinates of the ball in the reference frame they gave?

Answer 5

Yes, I used this

The acceleration of the ball in the x direction will be 0 as it will have the same speed throughout its fall. And it's acceleration in the Y direction will be -9.8m/s^2
Then the initial speed of the ball in the x direction is =cos(30)*5=4.33
the initial speed in the y direction of the ball is 2.55 by using Pythagorean.
Isn't this right.....................

Answer 6

oh the cart is moving when it's launched.. yes we have to include that velocity too...

Answer 7

your acceleration isn't right though, see the diagram.

Answer 8

so intial 'x' velocity shouldn't* be zero, it should be 5

Answer 9

you there?

Answer 10

not the initial velocity, the acceleration in the x direction is 0 for the ball

Answer 11

right

Answer 12

no.

Answer 13

then what is the acceleration of the ball in the x direction?

Answer 14

In y direction the acceleration is -9.8 m/s^2

Answer 15

can you not see the sketches?

Answer 16

let me look at them (viewing the skeches right now)

Answer 17

the frame you're in isn't y = vertical x = horizontal, it's the frame where x = up/down the ramp and y = into/out of the ramp.

Answer 18

isnt the x axis along the inclined track and the y axis is perpendicular to the inclined track

Answer 19

yes!

Answer 20

this is for the ball right

Answer 21

yes....

Answer 22

tell you what, draw the axes. then draw 'g' on them. see where the components of g are on your axes.

Answer 23

I see that the cart is accelerating but how will the ball have an acceleration in x direction

Answer 24

draw the axes. then draw 'g' on them. see where the components of g are on your axes.

Answer 25

the gravity will also work on the x direction for the ball..

Answer 26

yes

Answer 27

Is this because the cart shoots from an inclined track

Answer 28

as if it would shoot from a flat ground then no gravity would act on the x direction

Answer 29

and also its shot perpendicular to the inclined track

Answer 30

well, it's because you're looking at the ball in a frame that is oriented to the track. imagine a movie of the whole thing happening, and the viewing frame rotated so that the ramp face didn't appear inclined, but flat. That's what you're doing in this problem.

Answer 31

the ball would appear to go straight up at first while traveling to the right, but it wouldn't trace a parabola, it would be a flatter arc...

Answer 32

there would appear to be 'less' gravity, and the ball would have some mysterious force accelerating it to the right....

Answer 33

does this mean that when a ball is shot in an angle of 90 degrees then the gravity will have an effect on both its x and y direction