1. is D. Scientific method cannot be replaced.
2. is B.
3. is B as well.
Answer:

Explanation:
This is a projectile motion problem. We will first separate the motion into x- and y-components, apply the equations of kinematics separately, then we will combine them to find the initial velocity.
The initial velocity is in the x-direction, and there is no acceleration in the x-direction.
On the other hand, there no initial velocity in the y-component, so the arrow is basically in free-fall.
Applying the equations of kinematics in the x-direction gives

For the y-direction gives

Combining both equation yields the y_component of the final velocity

Since we know the angle between the x- and y-components of the final velocity, which is 180° - 2.8° = 177.2°, we can calculate the initial velocity.

The correct answer is B. it converts mechanical energy to electrical energy.
Answer: 0.5
Explanation:
The modulus of elasticity (called <em>"alargamiento unitario"</em> in spanish)
of a spring is given by the following formula:
Where:
is the original length of the spring
is the elongation of the spring, being
the length of the spring after a force is applied to it.
Then:
Potential energy = mgh
Potential energy = 10 x 9.8 x 1.3
Potential energy = 127.4 J