Newton's second law, \( F = m \times a \), calculates the braking force.
First, determine the acceleration. The car stops (\( v_f = 0 \) m/s) from an initial speed (\( v_i = 20 \) m/s) in \( t = 10 \) seconds.
Acceleration is calculated as:
\( a = \frac{v_f - v_i}{t} \)
Plugging in the values yields:
\( a = \frac{0 - 20}{10} = -2 \, \text{m/s}^2 \)
The negative acceleration signifies deceleration.
Next, use the force formula:
\( F = m \times a \)
With \( m = 1000 \, \text{kg} \) and \( a = -2 \, \text{m/s}^2 \):
\( F = 1000 \times (-2) = -2000 \, \text{N} \)
The negative sign indicates the braking force opposes motion. The average braking force magnitude is thus:
\( 2000 \, \text{N} \)