Acceleration

Answer Key - Grade 11 Science Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. 1.

   Ari times a car on a straight road. Its speed goes from 36 km/h to 90 km/h in 6 s. What is its acceleration in m/s²?

   2.5 m/s²
2. 2.

   Esme rides a train that speeds up on straight track, from 18 km/h to 108 km/h in 20 s. What is its acceleration in m/s²?

   1.25 m/s²
3. 3.

   In the velocity-time graph, the lines for carts A and B cross at 4 s. Which statement is true then, Jun?

   • Equal velocities, 10 m/s; A is speeding up and B is slowing
   • Equal accelerations, since the lines meet
   • B has the larger acceleration, since it started faster
   • Both carts have a = 0, since their velocities are equal
4. 4.

   West is negative. In the graph, a cart climbs from −8 m/s to 0 m/s in 4 s. What are its acceleration and motion, Kira?

   • 0 m/s², since the line ends at rest
   • +2 m/s², and the cart is slowing down
   • −2 m/s², since its velocity values are negative
   • +2 m/s², and the cart is speeding up
5. 5.

   In the velocity-time graph, what is the cart's acceleration between the two marked points, Luz?

   • 3 m/s²
   • 3.2 m/s²: the last velocity ÷ its time
   • 0.33 m/s²: the time change ÷ the velocity change
   • 12 m/s²: the whole rise in velocity
6. 6.

   A car is rated 0 to 60 mph in 3.0 s and a truck 0 to 60 mph in 6.0 s. What does that say, Milo?

   • The truck has twice the acceleration, since it takes twice as long
   • The car has twice the acceleration of the truck
   • The car has twice the speed of the truck
   • The two have the same acceleration, since both reach 60 mph
7. 7.

   A cart has a = 4 m/s² and v = 3 m/s when the clock reads 2 s. What is v when the clock reads 3 s, Noah?

   • 12 m/s, because 3 × 4
   • 15 m/s, because 4 m/s² acts for 3 s
   • 7 m/s: one more second adds 4 m/s
   • 4 m/s, because that is the acceleration
8. 8.

   A car rounds a bend at a steady 20 m/s. Is it accelerating, Pia?

   • No: its speed is steady, so a is zero
   • Yes: the direction changes, so v changes
   • No: acceleration means speeding up, not turning
   • Yes: any moving object is accelerating
9. 9.

   West is negative. A train has v = −12 m/s and a = −3 m/s². What is it doing, Ren?

   • Speeding up westward
   • Slowing down, since v is negative
   • Speeding up eastward
   • Slowing down, since a is negative
10. 10.

    West is negative. A train has v = −12 m/s and a = +3 m/s². What is it doing, Tala?

    • Slowing down; it stops after 36 s
    • Speeding up eastward, since a is positive
    • Slowing down; it stops after 4 s
    • Speeding up, since a is positive