| Exam Board | Edexcel |
|---|---|
| Module | M1 (Mechanics 1) |
| Year | 2016 |
| Session | January |
| Marks | 8 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Momentum and Collisions |
| Type | Given impulse, find velocity or mass |
| Difficulty | Moderate -0.3 This is a standard M1 collision problem requiring application of impulse-momentum theorem to find post-collision velocities. While it involves sign conventions and two-part calculation, it follows a routine textbook approach with no conceptual surprises—slightly easier than average due to its mechanical nature, though the arithmetic with fractions requires care. |
| Spec | 6.03b Conservation of momentum: 1D two particles6.03f Impulse-momentum: relation |
| Answer | Marks |
|---|---|
| 2(a) | (c) |
| Answer | Marks |
|---|---|
| 2(b) | First M1 for attempt at impulse = difference in momenta, for Q only, (i.e. must be |
| Answer | Marks |
|---|---|
| ALT | First M1 for attempt at CLM equation, with correct no. of terms, |
| Answer | Marks |
|---|---|
| ALT | They may find v first, then |
Question 2:
--- 2(a) ---
2(a) | (c)
--- 2(b) ---
2(b) | First M1 for attempt at impulse = difference in momenta, for Q only, (i.e. must be
using 3m and u). M0 if g’s are included on RHS
First A1 for either 33/ mu = 3m(v - -u) or 33/ mu = 3m(-v - -u) oe
5 Q 5 Q
Second dM1 for answer c/ u, where c is an integer, oe
5
Second A1 for 1.2u oe due E (or ‘reversed’ or ‘original direction of P)
But A0 if just ‘changed’ or ‘to the right’ or ‘in positive direction’
2(b)
ALT | First M1 for attempt at CLM equation, with correct no. of terms,
dimensionally correct, with their v substituted.
P
Allow consistent extra g’s and cancelled m’s and sign errors but masses and
velocities must be correctly matched.
First A1 for 2m.4u – 3mu = 2m.0.7u + 3m v oe or
Q
2m.4u – 3mu = 2m.0.7u - 3m v oe
Q
Second dM1 for answer c/ u, where c is an integer, oe
5
Second A1 for 1.2u oe due E
2(a)
ALT | They may find v first, then
Q
First M1 for attempt at CLM equation, with correct no. of terms,
dimensionally correct, with their v substituted.
Q
Allow consistent extra g’s and cancelled m’s and sign errors but masses and
velocities must be correctly matched.
First A1 for 2m.4u – 3mu = 2mv + 3m x 1.2u oe or
P
2m.4u – 3mu = - 2mv + 3m x 1.2u oe
P
Second dM1 for answer k/ u, where k is an integer, oe
10
Second A1 for 0.7u oe due E (or unchanged)Two particles $P$ and $Q$ are moving in opposite directions along the same horizontal straight line. Particle $P$ is moving due east and particle $Q$ is moving due west. Particle $P$ has mass $2m$ and particle $Q$ has mass $3m$. The particles collide directly. Immediately before the collision, the speed of $P$ is $4u$ and the speed of $Q$ is $u$. The magnitude of the impulse in the collision is $\frac{33}{5}mu$.
\begin{enumerate}[label=(\alph*)]
\item Find the speed and direction of motion of $P$ immediately after the collision. [4]
\item Find the speed and direction of motion of $Q$ immediately after the collision. [4]
\end{enumerate}
\hfill \mbox{\textit{Edexcel M1 2016 Q2 [8]}}