[brisbane]

Hi i am sorry but i can not write in Arabic my computer only writes English letters so please to not think i am trying to show of.

i have this two questions i have been trying to solve them but i do not know how , they are dynamic questions


1- A 42.8 kg girl is standing on a plank that has a mass of 158 kg. The plank, originally at rest, is free to slide on a frozen lake, which is a flat, frictionless supporting surface. The girl begins to walk along the plank at a constant speed of 1.41 m/s relative to the plank.

(a) What is her speed relative to the ice surface
(b) What is the speed of the plank relative to the ice surface?

the second qustion is

A block of mass 15.0 kg slides from rest down a frictionless incline and is stopped by a strong spring with The block slides 5.00 m from the point of release to the point where it comes to rest against the spring. When the block comes to rest, how far has the spring been compressed?

i would really appreciate it if u can help me and thank u so much.