Question 1

1. An athlete runs exactly halfway around a circular track of radius R = 70 m. What is the magnitude of their displacement?

A) 220 mB) 70 mC) 140 mD) 0 m

Answer

✓ Correct Answer: Option C

Explanation: Displacement is the shortest distance between the start and end points. For a semi-circle, this is the diameter. $$Displacement = 2 \times R = 2 \times 70 = 140 m$$

Question 2

2. A delivery drone travels 5 km at a speed of 20 km/h and then another 5 km at a speed of 60 km/h. What is the average speed for the entire 10 km trip?

A) 40 km/hB) 30 km/hC) 45 km/h

Question 3

3. A car's speedometer reads 72 km/h. What is this speed expressed in the SI unit (m/s)?

A) 20 m/sB) 25 m/sC) 15 m/sD) 10 m/s

Answer

✓ Correct Answer: Option A

Explanation: To convert km/h to m/s, multiply by $\frac{5}{18}$. $$72 \times \frac{5}{18} = 4 \times 5 = 20 m/s$$

Question 4

4. A mischievous monkey drops a mango from a tree branch 20 m above the ground. How long does it take to reach the ground? (Take $g = 10 m/s^2$)

A) 4 sB) 1 sC) 3 sD) 2 s

Answer

✓ Correct Answer: Option D

Explanation: Using $h = ut + \frac{1}{2}gt^2$ with u = 0: $$20 = 0 + \frac{1}{2} (10) t^2 ⇒ 20 = 5t^2 ⇒ t^2 = 4 ⇒ t = 2 s$$

Question 5

5. A robot moves 3 meters North and then 4 meters East. What is the magnitude of its total displacement from the starting point?

A) 7 mB) 5 mC) 1 mD) 12 m

Answer

✓ Correct Answer: Option B

Explanation: Displacement is the vector sum. Since North and East are perpendicular: $$D = \sqrt{3^2 + 4^2} = \sqrt{9 + 16} = \sqrt{25} = 5 m$$

Question 6

6. If a train is moving at a constant velocity of 15 m/s, what is its acceleration?

A) $0 m/s^2$B) $15 m/s^2$C) $9.8 m/s^2$D) $1 m/s^2$

Answer

✓ Correct Answer: Option A

Explanation: Acceleration is defined as the rate of change of velocity. If velocity is constant, the change is zero, so acceleration is $0 m/s^2$.

Question 7

7. On a Velocity-Time graph, a horizontal line (parallel to the time axis) represents:

A) Zero velocityB) Constant accelerationC) Constant velocityD) The object is at rest

Answer

✓ Correct Answer: Option C

Explanation: A horizontal line on a v-t graph means the velocity value does not change as time passes, which implies constant (uniform) velocity.

Question 8

8. A biker applying brakes reduces their speed from 20 m/s to 10 m/s in 5 seconds. What is the acceleration?

A) $2 m/s^2$B) $-2 m/s^2$C) $-5 m/s^2$D) $5 m/s^2$

Answer

✓ Correct Answer: Option B

Explanation: $$a = \frac{v - u}{t} = \frac{10 - 20}{5} = \frac{-10}{5} = -2 m/s^2$$ The negative sign indicates deceleration.

Question 9

9. Two cars A and B are driving on a highway in the same direction. Car A is at 80 km/h and Car B is at 100 km/h. What is the velocity of B relative to A?

A) 180 km/hB) -20 km/hC) 100 km/hD) 20 km/h

Answer

✓ Correct Answer: Option D

Explanation: Relative velocity $V_{BA} = V_B - V_A$ (when moving in the same direction). $$V_{BA} = 100 - 80 = 20 km/h$$

Question 10

10. Which of the following is a scalar quantity?

A) DistanceB) DisplacementC) VelocityD) Acceleration

Answer

✓ Correct Answer: Option A

Explanation: Scalar quantities have only magnitude and no direction. Distance is a scalar, while displacement, velocity, and acceleration are vectors.

Question 11

11. A ball is thrown horizontally from the top of a building. What happens to its horizontal velocity component (ignoring air resistance)?

A) It increases due to gravityB) It decreases until it hits the groundC) It remains constantD) It becomes zero immediately

Answer

✓ Correct Answer: Option C

Explanation: In projectile motion, there is no horizontal force (ignoring air), so the horizontal component of velocity ($u_x$) remains constant.

Question 12

12. A swimmer can swim at 4 m/s in still water. They try to swim straight across a river flowing at 3 m/s. What is their resultant speed?

A) 7 m/sB) 5 m/sC) 1 m/sD) 3.5 m/s

Answer

✓ Correct Answer: Option B

Explanation: The swimmer's velocity and river velocity are perpendicular. $$V_{res} = \sqrt{4^2 + 3^2} = \sqrt{16 + 9} = 5 m/s$$

Question 13

13. What does the area under a Velocity-Time graph represent?

A) AccelerationB) SpeedC) TimeD) Displacement

Answer

✓ Correct Answer: Option D

Explanation: The integral of velocity with respect to time (area under v-t graph) gives the change in position, which is displacement.

Question 14

14. A particle moves in a circle of radius r with constant speed v. The acceleration is:

A) Directed towards the centerB) Directed away from the centerC) Zero, because speed is constantD) Tangential to the path

Answer

✓ Correct Answer: Option A

Explanation: In uniform circular motion, even if speed is constant, the direction of velocity changes. This creates centripetal acceleration directed toward the center.

Question 15

15. A stone is thrown vertically upwards with an initial velocity u. At the highest point, its velocity is:

A) uB) 0C) 9.8 m/sD) -u

Answer

✓ Correct Answer: Option B

Explanation: At the maximum height of a vertical throw, the object momentarily stops before falling back down, so its instantaneous velocity is 0.

Question 16

16. A hiker walks 10 km North, then turns and walks 10 km South. What is their total distance traveled and total displacement?

A) Dist: 0 km, Disp: 20 kmB) Dist: 10 km, Disp: 10 kmC) Dist: 20 km, Disp: 0 kmD) Dist: 20 km, Disp: 20 km

Answer

✓ Correct Answer: Option C

Explanation: Distance is the total path length (10 + 10 = 20 km). Displacement is the change in position; since they returned to the start, displacement is 0.

Question 17

17. The slope of a Position-Time (x-t) graph represents:

A) VelocityB) AccelerationC) DistanceD) Force

Answer

✓ Correct Answer: Option A

Explanation: Slope = $\frac{\Delta x}{\Delta t}$, which is the definition of velocity.

Question 18

18. A car accelerates from rest at $4 m/s^2$. How far does it travel in 3 seconds?

A) 12 mB) 36 mC) 9 mD) 18 m

Answer

✓ Correct Answer: Option D

Explanation: Using $s = ut + \frac{1}{2}at^2$: $$s = 0(3) + \frac{1}{2}(4)(3^2) = 2 \times 9 = 18 m$$

Question 19

19. In projectile motion, the angle of projection for maximum horizontal range is:

A) $30^\circ$B) $45^\circ$C) $60^\circ$D) $90^\circ$

Answer

✓ Correct Answer: Option B

Explanation: The range formula is $R = \frac{u^2 \sin(2\theta)}{g}$. Range is maximum when $\sin(2\theta) = 1$, which happens at $2\theta = 90^\circ$, or $\theta = 45^\circ$.

Question 20

20. A plane flies 400 km East and 300 km North. What is the magnitude of its displacement?

A) 700 kmB) 100 kmC) 500 kmD) 350 km

Answer

✓ Correct Answer: Option C

Explanation: $$D = \sqrt{400^2 + 300^2} = \sqrt{160000 + 90000} = \sqrt{250000} = 500 km$$

Accepted Answer

✓ Correct Answer: Option B

Explanation: Average speed = Total Distance / Total Time. $$t_1 = \frac{5}{20} = 0.25 h, \quad t_2 = \frac{5}{60} = 0.0833 h$ $V_{avg} = \frac{10}{0.25 + 0.0833} = \frac{10}{0.333} = 30 km/h$$

Grade 11 : Physics - Motion (Straight/Plane) (Set 2)

1. An athlete runs exactly halfway around a circular track of radius R = 70 m. What is the magnitude of their displacement?

2. A delivery drone travels 5 km at a speed of 20 km/h and then another 5 km at a speed of 60 km/h. What is the average speed for the entire 10 km trip?

3. A car's speedometer reads 72 km/h. What is this speed expressed in the SI unit (m/s)?

4. A mischievous monkey drops a mango from a tree branch 20 m above the ground. How long does it take to reach the ground? (Take $g = 10 m/s^2$)

5. A robot moves 3 meters North and then 4 meters East. What is the magnitude of its total displacement from the starting point?

6. If a train is moving at a constant velocity of 15 m/s, what is its acceleration?

7. On a Velocity-Time graph, a horizontal line (parallel to the time axis) represents:

8. A biker applying brakes reduces their speed from 20 m/s to 10 m/s in 5 seconds. What is the acceleration?

9. Two cars A and B are driving on a highway in the same direction. Car A is at 80 km/h and Car B is at 100 km/h. What is the velocity of B relative to A?

10. Which of the following is a scalar quantity?

11. A ball is thrown horizontally from the top of a building. What happens to its horizontal velocity component (ignoring air resistance)?

12. A swimmer can swim at 4 m/s in still water. They try to swim straight across a river flowing at 3 m/s. What is their resultant speed?

13. What does the area under a Velocity-Time graph represent?

14. A particle moves in a circle of radius r with constant speed v. The acceleration is:

15. A stone is thrown vertically upwards with an initial velocity u. At the highest point, its velocity is:

16. A hiker walks 10 km North, then turns and walks 10 km South. What is their total distance traveled and total displacement?

17. The slope of a Position-Time (x-t) graph represents:

18. A car accelerates from rest at $4 m/s^2$. How far does it travel in 3 seconds?

19. In projectile motion, the angle of projection for maximum horizontal range is:

20. A plane flies 400 km East and 300 km North. What is the magnitude of its displacement?