Answer:
4.14 m
Explanation:
In the last leg of the journey the ball covers 2 m in 2ms or 0.2 s .
Let in this last leg , u be the initial velocity.
s = ut + 1/2 g t²
2 = .2 u + .5 x 9.8 x .04
u = 9.02 m /s .
Let v be the final velocity in this leg
v² = u² + 2 g s
v² = (9.02)² + 2 x 9.8 x 2
= 81.36 +39.2
v = 10.97 m / s
Now consider the whole height from where the ball dropped . Let it be h.
Initial velocity u = 0
v² = u² +2gh
(10.97 )² = 2 x 9.8 h
h = 6.14 m
Height from window
= 6.14 - 2m
= 4.14 m
Answer:
The mass has likely lost some of its mechanical energy to resistance on its path.
Explanation:
The mechanical energy of an object is the sum of its kinetic and potential energies (KE and PE.) Ideally, the mechanical energy of a simply pendulum should be "conserved." In other words, the sum of the kinetic and potential energy of the simply pendulum should stays the same as it travels along its path.
Indeed, as the pendulum travels, some of its PE will convert to KE and back. However, the sum of these two energies is supposed to stay the same.
- When the pendulum moves from the highest point to the bottom of the path, some of its PE converts to KE. (The pendulum speeds up in this process.)
- When the pendulum moves from the bottom of its path to the opposite side, its KE is converted back to PE. (The pendulum slows down as it moves towards the other side of the path.)
However, in practice, the mechanical energy of pendulums isn't always conserved. For example, various kinds of resistances (such as air resistance) act on the pendulum as it moves. That would slow down the pendulum. Some of the pendulum's energies would be converted to heat and is lost to the surroundings.
In effect, the mechanical energy of the pendulum would become smaller and smaller over time. When the pendulum travels back towards the girl, its potential energy would be smaller than the initial value when at the girl's chin.
Potential energy is energy stored in an object due to its position or arrangement. Kinetic energy is energy of an object due to its movement - its motion. ... Potential energy can be converted into kinetic energy, and kinetic energy can be converted into potential energy
A = -9.8
v = -9.8t -8
s = -4.9 t2 -8t +25
So… -5t^2 -8t + 25 =0, we’ll rearrange to 5t^2 + 8t - 25. We get two roots, one is positive and is 1.59 seconds
V = -9.8(1.59) - 8 = -23.6
So… it takes 1.59 seconds to hit the ground at -23.6 m/s.
Answer:
Densities increase down the group
MP and BP decrease down the group
Softness increased going down the group
Speed of reacting increases going down the group
