Answer:
-0.4D(maybe)
Explanation:
combined focal length (f)= 0.4m
D1 = 5D
Then f1= 1/D1
= 1/5 = 0.2 m
1/f=1/f1+1/f2
1/0.4=1/0.2+1/f2
f2= -5/2
D2=1/f2= -0.4D
Upper Mantle produces the magma that causes seafloor spreading and volcanoes. Other term for that is the lithosphere. It is a solid, outer part of the Earth, extending depth of around 100 kilometers. it includes the crust and the brittle upper portion of the mantle. It is the coolest and most rigid part of Earth.
(a) the initial kinetic energy of the projectile is equal to:

The projectile is fired straight up, so at the top of its trajectory, its velocity is zero; this means that it has no kinetic energy left, so for the law of conservation of energy, all its energy has converted into potential energy, which is equal to

b) If the projectile is fired with an angle of

, its velocity has 2 components, one in the x-direction and one in the y-direction:


This means that at the top of its trajectory, only the vertical velocity will be zero (because the horizontal velocity is constant, since the motion on the x-axis is a uniform motion). Therefore, at the top of the trajectory, the projectile will have some kinetic energy left:

For the conservation of energy, the initial energy mechanical energy must be equal to the mechanical energy at the highest point:

the initial kinetic energy is the same as point a), so we can re-arrange this equation to find the new potential energy at the top of the trajectory:
Answer:
When the muscle is completely contract.
Explanation:
Remember the that maximum force of a muscle is when is completely contract. A characteristic of a muscle is that can contract and can relax in the opposite direction. In this way, when all the microfibers of the muscle are join together (they are contract) is when the maximum tissue force is applied.
With exercise the fibers of the muscles can grow or reproduce to strength the muscle.