**Answer:**

20.353125 V

**Explanation:**

m = Mass of proton =

q = Charge of proton =

= Velocity of proton at A = 50 km/s

= Velocity of proton at B = 80 km/s

We have the relation by balancing the energy

**The potential difference is 20.353125 V**

The **conservation** of **energy** allows to find the result for the point where the **kinetic** and** potential energy **are **equal** is;

x = 0.026 m

**Given parameters**

- The mass of the body m = 220 g = 0.220 kg

- The force constant k = 7.0 N / m

- The initial displacement or amplitude xo = 5.2 cm = 0.052 m

**To find**

- The point where scientific and potential energy are equal.

The **law** of the** conservation** of **mechanical energy** is one of the most important in physics, stable that if there is **no friction**, the **mechanical energy** of the system is **conserved**. The **mechanical energy** is formed by the sum of the** kinetic energy** and the **potential energies**.

Em = K + U

Let's write the energy in two points.

**Starting point**. With **maximum compression.**

Em₀ = U = ½ k x²

**Final point**. Where the **kinetic** and** potential energy** are **equal**.

Since the **mechanical energy** is **constant** at this point **K = U**, therefore we can write the energy.

**Energy** is **conserved**.

Emo = Emf

½ k x² = 2 (½ k xf²)

let's calculate.

In conclusion using the** conservation** of **energy** we can find the **point **where the **kinetic** and **potential energy** are **equal **is;

x = 0.026 m

Learn more here: brainly.com/question/14688403

**Answer: D. 1.2 m**

**Explanation:**

According to the description, the boy, the side of the tent and the ground form a right triangle, which means we can solve this problem with a trigonometric function.

If in this right triangle the boy (whose length is ) and the ground are the sides of the triangle and the fabric that makes a angle with ground is the hypotenuse, we can use the function sine:

Isolating the :

**Finally: **

**This is the length of the fabric**