A 1000kg roller coaster begins at 10m tall hill with initial velocity of 6m/s and travels down until a second hill. 1700J is transformed to thermal engird by friction. In order for rollercoaster to get up 2nd hill it must have velocity of 4.6m/s or less at the top. What is the maximum height the second hill could be

The maximum height could be 10.6 meters.

Explanation:

For this kind of exercise, we use the general principle for conservation of mechanical energy (E) that states:

(1)

That means the mechanical energy an object has on a point 2 should be equal to the mechanical energy on a point 1 plus the energy transformed into heat due friction denoted as Wf (It is negative because is lost). In our case point 1 is the point where the roller coaster begins and point 2 is at the second hill. Tola mechanical energy is the sum of potential gravitational energy and kinetic energy, so (1) is :

with K the kinetic energy and U the potential energy, remember potential energy is mgh and kinetic energy is with m the mass, v the velocity and h the height, then:

Solving for h_2:

a and b sometimes have a positive value

get the total number of pieces of fruit and divide it by 4 to get the average. the result is the answer to the problem. 14 total number of fruits and there are 4 members. 14 divided by 4 is equals to 3.5.