I only know #2 and #4.
2.) cells
3.) cells, life , existing
Sorry that i dont know the rest but i took a test on this not to long ago, and i tend to forget stuff once i take a test on it.
Time=speed/acceleration
Gravitaional Acceleration=9.8 m/s^2
Speed=24.5 m/s
Time=24.5/9.8=2.5 s
When you climb, earth exerts gravitational force on pack in downward direction(pointing towards the center of earth).
In order to climb, you need to work against work done by gravity on the pack.
Hence work done by you = work done by gravity on pack
= Force x displacement = 70 x 30 = 2100 J.
So you need to do 2100 joules of work to lift your pack.
Power is the rate of work done.
Therefore power = work done by you/time(in seconds)
= 2100/600 =3.5 watts
Answer: v = 0.6 m/s
Explanation: <u>Momentum</u> <u>Conservation</u> <u>Principle</u> states that for a collision between two objects in an isolated system, the total momentum of the objects before the collision is equal to the total momentum of the objects after the collision.
Momentum is calculated as Q = m.v
For the piñata problem:


Before the collision, the piñata is not moving, so
.
After the collision, the stick stops, so
.
Rearraging, we have:


Substituting:

0.6
Immediately after being cracked by the stick, the piñata has a swing speed of 0.6 m/s.