Answer:

Explanation:
Average velocity is defined as the ratio of total displacement of the motion and total time taken in that motion
here we know that initially the sky diver drops without opening parachute by total displacement 625 m
then she open her parachute and drop another 362 m
so first it took time t = 15 s to drop without open parachute
then it took t = 139 s to drop next displacement
so here total displacement is given as

total time is given as

so average velocity is given as


Answer:
Magnitude of the net force on q₁-
Fn₁=1403 N
Magnitude of the net force on q₂+
Fn₂= 810 N
Magnitude of the net force on q₃+
Fn₃= 810 N
Explanation:
Look at the attached graphic:
The charges of the same sign exert forces of repulsion and the charges of opposite sign exert forces of attraction.
Each of the charges experiences 2 forces and these forces are equal and we calculate them with Coulomb's law:
F= (k*q*q)/(d)²
F= (9*10⁹*3*10⁻⁶*3*10⁻⁶)(0.01)² =810N
Magnitude of the net force on q₁-
Fn₁x= 0
Fn₁y= 2*F*sin60 = 2*810*sin60° = 1403 N
Fn₁=1403 N
Magnitude of the net force on q₃+
Fn₃x= 810- 810 cos 60° = 405 N
Fn₃y= 810*sin 60° = 701.5 N

Fn₃ = 810 N
Magnitude of the net force on q₂+
Fn₂ = Fn₃ = 810 N
Balance tubes by spacing them equally around the centrifuge and Always balance tubes with other tubes containing a same volume of liquid are right.
If you don't space them out equally, you will have a lot of broken glass to clean up...trust me. The same thing can happen if you don't have equal amounts of liquid in each tube, but it doesn't have to be exactly the same in every one.
No, energy transformation is occurring in every point of the motion.
In fact, the ball starts from point 1 with maximum kinetic energy and zero potential energy (taking the hand of the boy as reference level). The kinetic energy converts into gravitational potential energy as it goes higher: in point 2, part of the kinetic energy has converted into potential energy (because the velocity has decreased, while the height has increased), and then when the ball reaches point 3 all the kinetic energy has converted into potential energy (because now the velocity is zero, while the height is maximum). As the ball descends (point 4), the velocity starts to increase again, therefore the kinetic energy increases and the potential energy decreases (because the height is deacreasing now).
Summarizing, energy transformation is occuring in every point of the motion.
Same size as object should be the answer, it is a “plane” mirror