Martha drops a 1 kg rock off the top of Black Oak Canyon which is 100m deep. What is the KE of the rock the instant
before it hits bottom? Hint: Conservation of energy states that PE = KE
@bobpursley:
9.8*100 is actually 980, not 9800
Well, Martha sure knows how to have a rockin' time! Let's do some energy calculations to find out the kinetic energy of that falling rock.
The potential energy (PE) of an object is given by the formula PE = m * g * h, where m is the mass, g is the acceleration due to gravity (approximately 9.8 m/s^2), and h is the height.
So, in this case, the potential energy of the rock at the top of Black Oak Canyon can be calculated as PE = 1 kg * 9.8 m/s^2 * 100 m = 980 Joules.
According to the conservation of energy, this potential energy will be converted to kinetic energy (KE) as the rock falls.
So, the kinetic energy of the rock just before it hits the bottom will also be 980 Joules.
Now that's what I call rock 'n roll!
To calculate the kinetic energy (KE) of the rock just before it hits the bottom, we need to use the conservation of energy principle. According to this principle, potential energy (PE) is equal to kinetic energy.
Given:
Mass of the rock (m) = 1 kg
Height of Black Oak Canyon (h) = 100 m
The potential energy (PE) of the rock at the top of the canyon can be calculated using the formula:
PE = mgh
Where:
m = mass (in kg)
g = gravitational acceleration (approximately 9.8 m/s^2)
h = height (in meters)
Let's calculate the potential energy (PE) first:
PE = 1 kg * 9.8 m/s^2 * 100 m
= 980 Joules
Using the conservation of energy, we know that potential energy (PE) is equal to kinetic energy (KE) when the rock is about to hit the bottom. Therefore, the kinetic energy (KE) of the rock just before it hits the bottom is also 980 Joules.
To calculate the kinetic energy (KE) of the rock just before it hits the bottom of Black Oak Canyon, we need to use the principle of conservation of energy. The principle states that the potential energy (PE) of an object at a certain height is converted into kinetic energy as it falls.
The equation for potential energy is given by PE = mgh, where m is the mass of the object (1 kg in this case), g is the acceleration due to gravity (approximately 9.8 m/s²), and h is the height from which the object is dropped (100 m in this case).
In this scenario, the potential energy of the rock at the top of the canyon is entirely converted into kinetic energy at the moment it reaches the bottom. Therefore, the expression for conservation of energy can be written as:
PE = KE
Substituting the values into the equation:
mgh = KE
KE = mgh
KE = (1 kg) × (9.8 m/s²) × (100 m)
KE = 980 Joules
So, the kinetic energy of the rock just before it hits the bottom of Black Oak Canyon is 980 Joules.