Answer:
The value is 
Explanation:
From the question we are told that
The initial speed of the roller coaster is 
The length of the hill is 
The acceleration of the roller coaster is 
Generally the acceleration is mathematically represented as

Here
is the initial time which is equal to zero
is the final velocity which is mathematically represented as

So




Solving this using quadratic formula we obtain


Generally time cannot be negative so

Generally the final velocity is mathematically represented as


I barely do my own homework lol
Answer:
Work done, W = 750 joules
Explanation:
It is given that,
Force acting on the object, F = 50 N
It moves to a distance of, d = 15 meters
We need to find the work done on an object. We know that the product of force and distance covered is called the work done. As the force and the displacement are in same direction. So,


W = 750 joules
So, the work done on an object is 750 joules. Hence, this is the required solution.
Answer:
B) Caused by the Sun
Explanation:
If you look at a picture of a solar system, you will see the sun in the middle. The sun is the powerhouse of the solar system. So that means that the sun is the biggest star and can provide enough light to reach earth and keep it lit.