Ball a is dropped from the top of a building of height h at the same instant that ball b is thrown vertically upward from the ground. when the balls collide, they are moving n opposite directions, and the speed of a is twice the speed of b. at what height does the collision occur? (use any variable or symbol stated above as necessary.) both balls experience constant acceleration once they are �n flight. choose a coordinate system with the origin at the ground and the upward direction positive. when the balls collide they are at the same height above the ground.

2h / 3

Explanation:

Let after time t , collision occurs

distance covered by A

= 1/2gt²

Let u be the initial velocity with which B was thrown upwards

distance by B

= ut - 1/2 gt²

total distance by A and B

h = ut - 1/2 gt² +  1/2gt²

h = ut

t = h / u

velocity of A after t

= gt

= g x h/u

velocity of B after t

= u - gt

= u - g x h/u

given

g x h/u = 2 (u - g x h/u)

2u² - 2gh = gh

u =

t = h / u

=

Distance covered by A

= 1/2 gt²

= 1/2 x 2h/3

= h/3

Height at which collision occured

= h - h/3

= 2h /3

tube or goog with be a great resource to with that question

another example of kinetic energy would be,

kinetic energy   >     moving energy

answer   >   letter choice (c),   a hammer falling off a table.

hope that !                                         : )