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:

Answer:
(x,y) = (.5x,5y)
Step-by-step explanation:
Answer:
m + n = 15
m - 3 = n
The numbers are 9 and 6
Step-by-step explanation:
From the question,
The sum of two numbers is fifteen; the first number is m and the second number is n. To translate to a system of equations, we can write that
m + n = 15 ..... (1)
Also, from the question,
One number is three less than the other,
Also, to translate to a system of equations, we can write that
m - 3 = n ...... (2)
If desired, we can determine m and n
From equation (1)
m + n = 15
Then,
m = 15 - n ...... (3)
Put the value of m in equation (3) into equation (2)
m - 3 = n
Then
15 - n - 3 = n
15 - 3 = n + n
12 = 2n
n = 12/2
∴ n = 6
For m, put the value of n into equation 3
m = 15 - n
m = 15 - 6
m = 9
∴ m = 9 and n = 6
Hence, the numbers are 9 and 6
Answer: 44 boys and 40 girls
Step-by-step explanation:
x = number of girls
x + 4 = number of boys
x + x + 4 = 84
2x + 4 = 84
2x = 80
x = 40
84 - 40 = 44
Answer:
(Opt.B) 18
Step-by-step explanation:
4x = 2y - x (vertically opposite angles are equal)
4x + x = 2y
5x = 2y ----- (1)
4x + 2y + x = 180 (Linear pair angles)
5x + 2y = 180
From (1) we can understand that, the value of 5x and 2y is the same. So,
5x + 5x = 180
10x = 180
x = 180/10
x = 18
Just completing,
Putting the value of x in (1)
5*18 = 2y
90 = 2y
90/2 = y
45 = y
Hope you understand
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