To calculate the kinetic energy (KE) of the student riding her bicycle, you can use the formula:
\[ KE = \frac{1}{2} mv^2 \]
where:
- \(m\) is the mass in kilograms,
- \(v\) is the velocity in meters per second.
Given:
- \(m = 56\) kg
- \(v = 11\) m/s
Let's plug in the values:
\[ KE = \frac{1}{2} \times 56 , \text{kg} \times (11 , \text{m/s})^2 \]
First, calculate \( (11 , \text{m/s})^2 \):
\[ (11 , \text{m/s})^2 = 121 , \text{m}^2/\text{s}^2 \]
Now, substitute that back into the equation:
\[ KE = \frac{1}{2} \times 56 , \text{kg} \times 121 , \text{m}^2/\text{s}^2 \]
Calculate \( \frac{1}{2} \times 56 = 28\):
\[ KE = 28 , \text{kg} \times 121 , \text{m}^2/\text{s}^2 = 3,388 , \text{J} \]
Therefore, the kinetic energy of the student and her bicycle is 3,388 J.
The correct response is:
3,388 J.