micrometeor has a mass of 0.005 grams. When it enters Earth’s atmosphere, it travels at 21,000 meters per second. What is its kinetic energy when it enters Earth’s atmosphere?

KE=12mv2

(1 point)
Responses

1,102.5 J
1,102.5 J

1,102,500 J
1,102,500 J

2,205 J
2,205 J

0.0525 J
0.0525 J

1 answer

To calculate the kinetic energy (KE) of the micrometeor, 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

First, convert the mass from grams to kilograms:

\[ 0.005 \text{ grams} = 0.005 , \text{g} \times \frac{1 , \text{kg}}{1000 , \text{g}} = 0.000005 , \text{kg} \]

Next, substitute the values into the formula, using \( v = 21,000 , \text{m/s} \):

\[ KE = \frac{1}{2} \times 0.000005 , \text{kg} \times (21000 , \text{m/s})^2 \]

First, calculate \( (21000 , \text{m/s})^2 \):

\[ (21000)^2 = 441000000 \]

Now substitute this value into the kinetic energy formula:

\[ KE = \frac{1}{2} \times 0.000005 , \text{kg} \times 441000000 \]

Now compute:

\[ KE = 0.0000025 \times 441000000 = 1102.5 , \text{J} \]

Therefore, the kinetic energy when the micrometeor enters Earth’s atmosphere is:

1,102.5 J.