Question

If a 900 kg cow stampedes at 10 m/s, what is the cows kinetic energy?

90j
9000j
45,000j
4500j

Answer 1

45,000 J

General Formulas and Concepts:

Energy

Kinetic Energy Formula:
`\displaystyle KE = (1)/(2)mv^2`

• m is mass (in kg)
• v is velocity (in m/s)

Step-by-step explanation:

Step 1: Define

Identify variables

[Given] m = 900 kg

[Given] v = 10 m/s

Step 2: Solve for KE

1. Substitute in variables [Kinetic Energy Formula]:
   `\displaystyle KE = (1)/(2)(900 \ kg)(10 \ m/s)^2`
2. Evaluate exponents:
   `\displaystyle KE = (1)/(2)(900 \ kg)(100 \ m^2/s^2)`
3. Multiply:
   `\displaystyle KE = (450 \ kg)(100 \ m^2/s^2)`
4. Multiply:
   `\displaystyle KE = 45000 \ J`