Laws of Motion

⏱ Time: 0s

Q1. A 50 kg object is dropped from a height of 20 m. What is the speed just before it hits the ground? (g = 10 m/s²) (2020)

Solution:

Using v² = u² + 2gh, v² = 0 + 2 * 10 m/s² * 20 m = 400, v = √400 = 20 m/s.

⏱ Time: 0s

Q2. A 15 kg object is dropped from a height. What is the force acting on it due to gravity? (2023)

Solution:

Using F = mg, where g = 9.8 m/s², we have F = 15 kg * 9.8 m/s² = 147 N, which rounds to 150 N.

⏱ Time: 0s

Q3. A 2 kg object is subjected to a net force of 8 N. What is its acceleration? (2020)

Solution:

Using F = ma, a = F/m = 8 N / 2 kg = 4 m/s².

⏱ Time: 0s

Q4. A 15 kg object is moving with a velocity of 4 m/s. What is its momentum? (2019)

Solution:

Momentum = mass × velocity = 15 kg × 4 m/s = 60 kg m/s.

⏱ Time: 0s

Q5. A block of mass 5 kg is resting on a frictionless surface. A force of 10 N is applied to it. What will be its acceleration? (2020)

Solution:

Using Newton's second law, F = ma, acceleration (a) = F/m = 10 N / 5 kg = 2 m/s².

⏱ Time: 0s

Q6. If a force of 15 N is applied to a mass of 3 kg, what is the acceleration of the mass? (2023)

Solution:

Using F = ma, a = F/m = 15 N / 3 kg = 5 m/s².

⏱ Time: 0s

Q7. A 15 kg box is pulled with a force of 60 N at an angle of 30° to the horizontal. What is the horizontal component of the force? (2022)

Solution:

Horizontal component = F * cos(θ) = 60 N * cos(30°) = 60 N * (√3/2) = 51.96 N.

⏱ Time: 0s

Q8. A 10 kg object is thrown vertically upward with a speed of 20 m/s. What is the maximum height reached by the object? (g = 10 m/s²) (2020)

Solution:

Using the formula h = v² / (2g), h = (20 m/s)² / (2 * 10 m/s²) = 20 m.

⏱ Time: 0s

Q9. A car accelerates from rest at a constant rate of 2 m/s². How far does it travel in 5 seconds? (2021)

Solution:

Using the equation of motion: s = ut + (1/2)at². Here, u = 0, a = 2 m/s², t = 5 s. So, s = 0 + (1/2)(2)(5²) = 25 m.

⏱ Time: 0s

Q10. A ball is thrown vertically upwards with a speed of 20 m/s. How high will it go? (g = 10 m/s²) (2023)

Solution:

Using the formula h = v²/(2g), we have h = (20 m/s)² / (2 * 10 m/s²) = 20 m.