Calculate the kinetic or potential energy in joules for each of the following situations:
A. A 2.5 kg book is held 2.0 m above the ground.
B. A 15 g snowball is moving through the air at 3.5 m/s.
C. A 35 kg child is sitting at the top of a slide that is 3.5 m above the ground.
D. An 8,500 kg airplane is flying at 220 km/h.
A-potential:49j
B- kinetic: 0.091875j
C-potential:437.5j
D-potential:
To calculate the kinetic or potential energy in joules for each of the situations provided, we need to use the appropriate formulas.
A. To calculate the potential energy of the book held above the ground, we can use the formula:
Potential Energy = mass * gravitational acceleration * height
Given:
mass (m) = 2.5 kg
height (h) = 2.0 m
gravitational acceleration (g) = 9.8 m/s^2
Substituting the values into the formula:
Potential Energy = 2.5 kg * 9.8 m/s^2 * 2.0 m
Calculating the potential energy:
Potential Energy = 49 Joules
Therefore, the potential energy of the book is 49 Joules.
B. To calculate the kinetic energy of the snowball in motion, we can use the formula:
Kinetic Energy = 0.5 * mass * velocity^2
Given:
mass (m) = 15 g = 0.015 kg
velocity (v) = 3.5 m/s
Substituting the values into the formula:
Kinetic Energy = 0.5 * 0.015 kg * (3.5 m/s)^2
Calculating the kinetic energy:
Kinetic Energy = 0.5 * 0.015 kg * 12.25 m^2/s^2
Kinetic Energy = 0.0919 Joules or approximately 0.092 Joules
Therefore, the kinetic energy of the snowball is approximately 0.092 Joules.
C. To calculate the potential energy of the child sitting at the top of the slide, we can use the same formula as in situation A:
Potential Energy = mass * gravitational acceleration * height
Given:
mass (m) = 35 kg
height (h) = 3.5 m
gravitational acceleration (g) = 9.8 m/s^2
Substituting the values into the formula:
Potential Energy = 35 kg * 9.8 m/s^2 * 3.5 m
Calculating the potential energy:
Potential Energy = 1221.5 Joules or approximately 1222 Joules
Therefore, the potential energy of the child is approximately 1222 Joules.
D. To calculate the kinetic energy of the airplane flying, we can use the formula:
Kinetic Energy = 0.5 * mass * velocity^2
Given:
mass (m) = 8,500 kg
velocity (v) = 220 km/h = 61.1 m/s
Substituting the values into the formula:
Kinetic Energy = 0.5 * 8,500 kg * (61.1 m/s)^2
Calculating the kinetic energy:
Kinetic Energy = 0.5 * 8,500 kg * 3732.1 m^2/s^2
Kinetic Energy = 0.5 * 317,061,500 kg * m^2/s^2
Kinetic Energy = 158,530,750 Joules or approximately 1.59 x 10^8 Joules
Therefore, the kinetic energy of the airplane is approximately 158,530,750 Joules or 1.59 x 10^8 Joules.
Why me?
A.) 0 because it's not in motion
B.) 91.875 J
C.)1,201.725 J
D.) 205,700,000 J