Define the term momentum in words - NSC Technical Sciences - Question 3 - 2023 - Paper 1

To find the final velocity after the collision, we can use the principle of conservation of momentum. The formula is:

$m_A v_{A_i} + m_B v_{B_i} = (m_A + m_B)v_f$

Using the given values:

• Mass of player A, $m_A = 100 ext{ kg}$, velocity $v_{A_i} = 5 ext{ m/s}$
• Mass of player B, $m_B = 75 ext{ kg}$, velocity $v_{B_i} = -4 ext{ m/s}$ (negative because it's in the opposite direction)

Calculating:

$100 imes 5 + 75 imes (-4) = (100 + 75)v_f$

$500 - 300 = 175v_f$

$200 = 175v_f$

v_f = rac{200}{175} ext{ m/s} = 1.14 ext{ m/s}

Thus, the final velocity of both players moving together is approximately $1.14 ext{ m/s}$.

The principle applied is the conservation of linear momentum, which states that the total linear momentum of a closed system remains constant if no external forces act upon it.

Newton's Second Law of Motion states that the net force acting on an object is equal to the rate of change of its momentum in the direction of the net force.

To calculate the area under the graph, we recognize that the shape is a triangle. The area $A$ can be calculated using the formula for the area of a triangle:

A = rac{1}{2} imes ext{base} imes ext{height}

From graph A:

• Height (Force) = 200 N
• Base (Time) = 2 s

Thus:

A = rac{1}{2} imes 2 imes 200 = 200 ext{ Ns}

The area under the net force versus time graph represents the impulse experienced by the object.

To illustrate the net force versus time graph for the softer squash ball, you should replicate graph A but note that the shape may vary since the ball may have different rebound characteristics. Ensure to label the new graph as graph B. Sketch it with similar axes, considering the impulse will remain the same but may differ in detail due to material properties.

1. Crumple zones: These are areas in the front and rear of vehicles designed to deform and absorb energy during a collision, thus extending the time taken for the car to stop.

2. Airbags: These deploy upon collision and inflate quickly to cushion the occupants, reducing the force of impact by increasing the time over which momentum is brought to zero.

Crumple zones reduce injuries by increasing the time taken for the vehicle to come to a complete stop during a collision. This increase in time decreases the net force experienced by the occupants, following the impulse-momentum theorem. The longer time allows for a more gradual reduction in momentum, thus lowering the forces acting on the passengers. By reducing the net force, injuries from sudden stops can be minimized.