I believe the process you have described is known as an 'experiment'.
Answer:
4.6s
Explanation:
v=u+at
0=22.5+(-9.8)t
-22.5=-9.8t
t=-22.5/-9.8
t=2.295 s
The total time will double
2.295×2=4.59s
=4.6s
Answer:
To have a positive job, the two vectors must have the same direction
Explanation:
Work is a scalar defined as the scalar product of two vectors, the froce and the displacement. To have a positive job, the two vectors must have
collinear and that their arrows point in the same direction.
You can also appreciate this from the work equation
W = F. r
bold indicate vector
W = F r cos θ
With θ the angle between force and displacement
I don’t know ask your parents