Jacob is a little too excited about finishing his homework and throws his hands up in the to shout, "I'm done!" He accidentally drops his 2.3 kg pencil straight down from a height of 2.12 m. what will be the kinetic energy of the pencil just before it hits the ground?
(1/2) m v^2 = m g h
2.3 kg?
That's some pencil!!
You sure you did not mean 2.3 g? That's too light.
You sure you meant pencil?
To calculate the kinetic energy of the pencil just before it hits the ground, we need to use the formula for kinetic energy:
Kinetic energy (KE) = 1/2 * mass * velocity^2
To find the velocity of the pencil just before it hits the ground, we can use the principle of conservation of energy. The potential energy of an object at a certain height is given by:
Potential energy (PE) = mass * gravitational acceleration * height
In this case, the height is 2.12 m, the mass of the pencil is 2.3 kg, and the gravitational acceleration is approximately 9.8 m/s^2. Thus, we have:
PE = 2.3 kg * 9.8 m/s^2 * 2.12 m = 47.6156 Joules (approximately)
This potential energy will be converted entirely into kinetic energy just before the pencil hits the ground. Therefore, the kinetic energy of the pencil just before it hits the ground will be equal to the potential energy:
KE = 47.6156 Joules (approximately)
So, the kinetic energy of the pencil just before it hits the ground will be approximately 47.6156 Joules.