QuestionKinetic energy varies jointly as the mass and the square of the velocity. A mass of 6 grams and velocity of 3 centimeters per second has a kinetic energy of 27 ergs. Find the kinetic energy for a mass of 2 grams and velocity of 6 centimeters per second.
A mass of 2 grams and velocity of 6 centimeters per second has a kinetic energy of ergs.
Studdy Solution
STEP 1
What is this asking?
If we know the kinetic energy of a moving object with a certain mass and speed, can we figure out the kinetic energy of another object with a different mass and speed, assuming kinetic energy, mass, and speed are related in a specific way?
Watch out!
Don't forget to square the velocity!
It's a common mistake to miss that little detail.
Also, "varies jointly" has a specific mathematical meaning, so let's make sure we understand what that means!
STEP 2
1. Define the relationship
2. Find the constant of proportionality
3. Calculate the new kinetic energy
STEP 3
Alright, so "kinetic energy varies jointly as the mass and the square of the velocity." What does *that* even mean?! It means kinetic energy is *directly proportional* to both the mass and the square of the velocity.
In simpler terms, if one goes up, the others go up too!
STEP 4
Mathematically, we can write this relationship as:
Where is the **kinetic energy**, is the **mass**, is the **velocity**, and is our mysterious **constant of proportionality**.
We gotta find *that* guy!
STEP 5
We're given that a mass of **6 grams** and a velocity of **3 centimeters per second** results in a kinetic energy of **27 ergs**.
Let's plug those values into our formula:
STEP 6
Now, let's simplify and solve for : To isolate , we divide both sides by 54: So, our **constant of proportionality**, , is !
STEP 7
Now that we know , we can use our formula to find the kinetic energy for a mass of **2 grams** and a velocity of **6 centimeters per second**:
STEP 8
Let's crunch those numbers: Boom! The kinetic energy is **36 ergs**!
STEP 9
The kinetic energy for a mass of 2 grams and velocity of 6 centimeters per second is 36 ergs.
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