Answer:
The kinetic energy is 20,000\ J
Step-by-step explanation:
The kinetic energy of a body is defined as:

Where <em>m</em> is the mass of the roller coaster car
<em>s</em> is the speed and <em>k</em> is the kinetic energy
We know that 

Then the kinetic energy of the roller coaster car is:

A triangle is the anwser because it is made of many triangles
Answer:
(3,-4)
Step-by-step explanation:
85/100
17/20 when simplified
Lets assume center point of circle as O
OD is the radius of circle . so OD is also 7
All the sides of the triangle are equal . so angle at the center O is 60 degree.
radius = 7
Length of arc CD = 
= 
= 
= 