A boy with a mass of 30 kg jumps off a 3 m diving board. How much kinetic energy does he have just before he hits the water?
Answer
none.
90 N.
900 J.
1800 J.
what is mass*g*height?
The diving board is 3m above the floor that's all the information i was given
The diving board is 3m above the floor that's all the information we were given
To calculate the kinetic energy (KE) of the boy just before he hits the water, we can use the following formula:
KE = 1/2 * m * v^2
Where:
KE = Kinetic Energy
m = Mass of the boy (in kg)
v = Velocity of the boy (in m/s)
To find the velocity, we can use the equation:
v = sqrt(2 * g * h)
Where:
g = Acceleration due to gravity (9.8 m/s^2)
h = Height of the diving board (in meters)
Given:
Mass of the boy (m) = 30 kg
Height of the diving board (h) = 3 m
Acceleration due to gravity (g) = 9.8 m/s^2
First, calculate the velocity (v):
v = sqrt(2 * g * h)
v = sqrt(2 * 9.8 * 3)
v = sqrt(58.8)
v ≈ 7.67 m/s
Now, substitute the values of mass (m) and velocity (v) into the KE formula:
KE = 1/2 * m * v^2
KE = 1/2 * 30 * (7.67)^2
KE = 1/2 * 30 * 58.84
KE ≈ 8814.0 J
Therefore, the boy has approximately 8814 J of kinetic energy just before he hits the water.
Based on the answer choices provided, the closest option is 900 J. However, the correct answer is approximately 8814 J.