NEET Kinematics — Set 14

Question 1

A stone is dropped from rest. What is the distance covered in the 5th second of its fall? (Take $ g = 10 \, \text{m/s}^2 $)

Accepted Answer

Distance in $ n $-th second = $ g \cdot \frac{2n - 1}{2} $. For 5th second, $ n = 5 $. Substitute: $ d = 10 \cdot \frac{2 \cdot 5 - 1}{2} = 10 \cdot \frac{9}{2} = 45 \, \text{m} $. The distance covered is $ 45 \, \text{m} $.

Question 2

A train accelerates uniformly from $ 20 \, \text{m/s} $ to $ 40 \, \text{m/s} $ in $ 10 \, \text{s} $. What is the distance covered?

Accepted Answer

Find $ a = \frac{v - v_0}{t} = \frac{40 - 20}{10} = 2 \, \text{m/s}^2 $. Use $ x = v_0 t + \frac{1}{2} a t^2 = 20 \cdot 10 + \frac{1}{2} \cdot 2 \cdot (10)^2 = 200 + 100 = 300 \, \text{m} $. The distance covered is $ 300 \, \text{m} $.

Question 3

A man walks $ 4 \, \text{km} $ in $ 1 \, \text{hour} $ and then returns to the starting point in $ 1 \, \text{hour} $. What is his average speed?

Accepted Answer

Average speed = total distance / total time. Total distance = $ 4 \, \text{km} + 4 \, \text{km} = 8 \, \text{km} $, total time = $ 1 \, \text{h} + 1 \, \text{h} = 2 \, \text{h} $. Average speed = $ \frac{8}{2} = 4 \, \text{km/h} $.

NEET Physics: Kinematics — Practice Set 14

Q1. A stone is dropped from rest. What is the distance covered in the 5th second of its fall? (Take \( g = 10 \, \text{m/s}^2 \))

Q2. A train accelerates uniformly from \( 20 \, \text{m/s} \) to \( 40 \, \text{m/s} \) in \( 10 \, \text{s} \). What is the distance covered?

Q3. A man walks \( 4 \, \text{km} \) in \( 1 \, \text{hour} \) and then returns to the starting point in \( 1 \, \text{hour} \). What is his average speed?

Q4. A cyclist moves at a constant speed of \( 12 \, \text{m/s} \) for \( 30 \, \text{s} \). What is the distance covered?

Q5. A ball is thrown vertically upwards with \( 30 \, \text{m/s} \). How long does it take to return to the ground? (Take \( g = 10 \, \text{m/s}^2 \))

Q6. A car accelerates uniformly from \( 5 \, \text{m/s} \) to \( 25 \, \text{m/s} \) in \( 10 \, \text{s} \). What is the distance traveled?

Q7. A car accelerates from \( 8 \, \text{m/s} \) at \( 2 \, \text{m/s}^2 \) for \( 5 \, \text{s} \), then moves at constant speed for \( 3 \, \text{s} \). What is the average speed over the entire motion?

Q8. A truck moving at \( 144 \, \text{km/h} \) decelerates uniformly and stops in \( 12 \, \text{s} \). What is the magnitude of deceleration?

Q9. A car accelerates uniformly from rest at \( 4 \, \text{m/s}^2 \) for \( 5 \, \text{s} \). What is the final velocity?

Q10. A cyclist moves at a constant speed of \( 6 \, \text{m/s} \) for \( 50 \, \text{s} \). What is the distance covered?