When Jane falls, her skateboard rolls down a ramp at a speed of 2.6 meters per second. If the skateboard has a mass of 3 kilograms, how much kinetic energy does it have?

KE=12mv2

(1 point)
Responses

11.7 J
11.7 J

20.28 J
20.28 J

10.14 J
10.14 J

3.9 J

1 answer

To calculate the kinetic energy (KE) of the skateboard, we can use the formula:

\[ KE = \frac{1}{2} m v^2 \]

Where:

  • \( m \) is the mass of the skateboard (in kilograms)
  • \( v \) is the speed of the skateboard (in meters per second)

Given:

  • \( m = 3 \) kg
  • \( v = 2.6 \) m/s

Now, substituting the values into the formula:

\[ KE = \frac{1}{2} \times 3 , \text{kg} \times (2.6 , \text{m/s})^2 \] \[ = \frac{1}{2} \times 3 \times 6.76 \quad \text{(since } 2.6^2 = 6.76\text{)} \] \[ = \frac{1}{2} \times 20.28 \] \[ = 10.14 , \text{J} \]

Thus, the kinetic energy of the skateboard is 10.14 J.