AP Physics C: Mechanics 1.3 Representing Motion Questions

(i)

For stating that the area bounded by the curve is the displacement

1 point

(a)(ii)

For indicating momentum is conserved

1 point

Example Response

$\Sigma p_0=\Sigma p_f$

For the correct answer for speed with units (2 m/s)

1 point

Example Solution

$m_{\mathrm A}v_{\mathrm{A0}}+m_{\mathrm B}v_{\mathrm{B0}}=m_{\mathrm A}v_{\mathrm{Af}}+m_{\mathrm B}v_{\mathrm{Bf}}$$m_{\mathrm A}v_{\mathrm{A0}}-m_{\mathrm A}v_{\mathrm{Af}}=m_{\mathrm B}v_{\mathrm{Bf}}$$v_{\mathrm{Bf}}=\frac{m_{\mathrm A}}{m_{\mathrm B}}\left(v_{\mathrm{A0}}-v_{\mathrm{Af}}\right)$$v_{\mathrm{Bf}}=\frac{1000\,\mathrm{kg}}{2000\,\mathrm{kg}}(5\,\mathrm{m/s}-1\,\mathrm{m/s})$$\therefore v_{\mathrm{Bf}}=2\,\mathrm{m/s}$

For a graph that starts at (0,0) and ends at (0.5,2) or value consistent with (a)(ii)

1 point

For a smooth, continuous curve that transitions from concave up to concave down

1 point

Example Solution

$v(\mathrm{m/s})$$v(\mathrm{m/s})$

Total for part (a)

5 points