A ball falls from a tall bridge. The ball has a mass of 0.15 kg. The air density is 1.225 kg/m3

. The ball’s surface area is 0.0026 m2
. The ball’s coefficient of drag is 0.007. What is the ball’s terminal velocity?(1 point)
Responses

402 m/s
402 m/s

30.4 m/s
30.4 m/s

363 m/s
363 m/s

164 m/s
164 m/s

1 answer

To calculate the terminal velocity of the ball, you can use the following formula:

\[ v_t = \sqrt{\frac{2mg}{\rho C_d A}} \]

Where:

  • \( v_t \) is the terminal velocity (m/s)
  • \( m \) is the mass of the object (kg)
  • \( g \) is the acceleration due to gravity (approximately \( 9.81 , \text{m/s}^2 \))
  • \( \rho \) is the air density (kg/m³)
  • \( C_d \) is the drag coefficient (dimensionless)
  • \( A \) is the cross-sectional area (m²)

Given:

  • \( m = 0.15 , \text{kg} \)
  • \( g = 9.81 , \text{m/s}^2 \)
  • \( \rho = 1.225 , \text{kg/m}^3 \)
  • \( C_d = 0.007 \)
  • \( A = 0.0026 , \text{m}^2 \)

Substituting the values into the formula:

\[ v_t = \sqrt{\frac{2 \times 0.15 , \text{kg} \times 9.81 , \text{m/s}^2}{1.225 , \text{kg/m}^3 \times 0.007 \times 0.0026 , \text{m}^2}} \]

Calculating the numerator:

\[ 2 \times 0.15 , \text{kg} \times 9.81 , \text{m/s}^2 = 2.9415 , \text{kg m/s}^2 \]

Calculating the denominator:

\[ 1.225 , \text{kg/m}^3 \times 0.007 \times 0.0026 , \text{m}^2 = 0.000022365 , \text{kg/m} \]

Now, substituting back to calculate \( v_t \):

\[ v_t = \sqrt{\frac{2.9415}{0.000022365}} \approx \sqrt{131,011.167} \]

Calculating the final result:

\[ v_t \approx 362.11 , \text{m/s} \]

Based on this computation, rounding to the nearest whole number gives:

Terminal velocity \( v_t \) is approximately 363 m/s.

Therefore, the correct response is 363 m/s.