Question

PLEASE HELP!!?

Answer 1

i think it will reach d and then fall back down but im not completely sure....

Answer 2

if it had no initial velocity then you can see that it will 'fall down the trough A-C
In doing so it converts it PE at A to KE at C
It would then roll UP th eslope for C towards D, gaining PE and losing KE in the process. You can see therefore that if it had no initial velocity it would come to rest at a point between D and E - exactly level with A.

SO
We now add in the KE which it has initially at A - (mv^2)/2
Point E is 0.5 m above A (and above the equivalent point between D and E)

SInce the motion is frictionless it will have the same KE at that point as it had at A
To reach E it needs to increase its PE by rising another 0.5m

So the question is - Is the re sufficient KE at A to raise the mass by 0.5m

KE = (mv^2)/2 PE = mgh

Answer 3

Yes, another statement of it is that the initial kinetic energy and potential energy must be greater or equal to the potential energy at E
for the kinetic energy there at E to be greater than zero.

(1/2) m v^2 + m g h >= m g h' ? mass cancels out

(1/2) v^2 + g h >= g h' ?

(1/2)(1.0)^2 + (9.8)(2.5) >= (9.8)(3.0) ?