A computational model predicts the speed of a roller coaster car at different heights given its speed at the lowest height of its journey, which is at ground level. The speed at the lowest point is 30 m/s. What is the prediction for its speed when it is at a height of 20 m? A. 22.5 m/s
B. 37.5 m/s
C. 18.8 m/s
D. 15.9 m/s

the answers, the correct one is A   v= 22.5 m/s

Explanation:

We can solve this problem using the concepts of conservation of mechanical energy

Starting point. Lowest point of the trajectory

       Em₀ = K = ½ m v₀²

Final point. When it is at a height of y = 20 m

        = K + U = ½ m v² + mg y

how energy is conserved

         Emo = Emf

         ½ m v₀² = ½ m v² + m g y

         v² = v₀² + 2 g y

let's calculate

         v²2 = 30 2 + 2 9.8 20

         v² = 508

         v²= ra 508

         v² = 22.54 m / s

When checking the answers, the correct one is A

answer: d. a cme increases the amount of energy in the solar wind

explanation:

coronal mass ejections, also called cmes, are large clouds of plasma and magnetic field that erupt from the sun. only when the cloud is aimed at earth will the cme hit earth and therefore cause impacts. high-speed solar wind streams come from areas on the sun known as coronal holes.

answer; equivalent to a one(1) horsepower motor;