Velocity and Acceleration

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Des questions tirées de vraies épreuves CSCA qui portent sur ce concept. Essayez de les résoudre avant d'afficher la réponse.

1. CSCA Physics December 2025 Past Paper
   As shown in the figure, an object moves from point $A$ through point $B$ to point $C$ along two semicircles with radius $R = 6 \mathrm {~m}$, taking a time of $t = 4 \mathrm {~s}$. The magnitude of its average velocity is ().
   • A．$6 \mathrm {~m} / \mathrm { s }$
   • B．$12 \mathrm {~m} / \mathrm { s }$
   • C．$6 \pi \mathrm {~m} / \mathrm { s }$
   • D．$3 \pi \mathrm {~m} / \mathrm { s }$
   Afficher la réponse et la solution

   Réponse : A

   1 Displacement is the straight line from A to C. The two semicircles each have diameter $2 R = 12 \mathrm {~m}$, so the displacement is $x = 4 R = 24 \mathrm {~m}$. 2 Average velocity $= x / t = 24 \mathrm {~m} / 4 \mathrm {~s} = 6 \mathrm {~m} / \mathrm { s }$, option A. 3 Note: the path length is $2 \pi R = 12 \pi \mathrm {~m}$, so $3 \pi \mathrm {~m} / \mathrm { s }$ (option D) is the average speed, not the average velocity.
   Voir dans l'épreuve complète CSCA Physics December 2025 Past Paper
2. CSCA Physics March 2026 Past Paper
   The x-t graph for a toy car in linear motion is shown. Which statement is correct?
   • A．Displacement from $0 - 4 \mathrm {~s}$ is 8 m
   • B．Velocity from $0 - 4 \mathrm {~s}$ is $1.0 \mathrm {~m} / \mathrm { s }$
   • C．Average velocity from $0 - 5 \mathrm {~s}$ is $0.8 \mathrm {~m} / \mathrm { s }$
   • D．Velocity from $4 - 5 \mathrm {~s}$ is $0.8 \mathrm {~m} / \mathrm { s }$
   Afficher la réponse et la solution

   Réponse : B

   From graph: $0 - 4 \mathrm {~s} , x$ goes from 0 to 4 m linearly. A: displacement is 4 m , not 8 . $B : v = 4 / 4 = 1.0 \mathrm {~m} / \mathrm { s }$, correct. C: at 5 s position returns to 0 , average velocity $= 0 / 5 = 0$. D: $4 - 5 \mathrm {~s}$, displacement $= 4 \mathrm {~m}$ in 1 s , speed $= 4 \mathrm {~m} / \mathrm { s }$. Answer: B.
   Faire l'épreuve complète CSCA Physics March 2026 Past Paper — chronométrée et notée
3. CSCA Physics April 2026 Past Paper
   As shown in the figure, an object travels along a path consisting of two semicircles end-to-end (each of radius 4 m ) from $A$ through $B$ to $C$. Points $A , B , C$ are collinear along the east-west direction. The travel takes 2 s . The magnitude of the average velocity is
   • A．$4 \mathrm {~m} / \mathrm { s }$
   • B．$0 \mathrm {~m} / \mathrm { s }$
   • C．$2 \mathrm {~m} / \mathrm { s }$
   • D．$8 \mathrm {~m} / \mathrm { s }$
   Afficher la réponse et la solution

   Réponse : D

   Each semicircle has diameter $2 R = 8 \mathrm {~m}$, so $| A B | = | B C | = 8 \mathrm {~m}$. Because $A$, $B , C$ are collinear, the total displacement is $| A C | = 16 \mathrm {~m}$. Average velocity $= \frac { | A C | } { t } = \frac { 16 } { 2 } = 8 \mathrm {~m} / \mathrm { s }$.
   Faire l'épreuve complète CSCA Physics April 2026 Past Paper — chronométrée et notée