Category: HC Verma Part 1: Mechanics
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HC Verma Chapter 6 Problem 15 — Block pushed by two forces: friction and net force
Problem Statement Solve the Newton’s Laws / mechanics problem: A 4 kg block is on a rough horizontal surface ($\mu_k = 0.25$). Two horizontal forces $F_1 = 20$ N and $F_2 = 8$ N act in the same direction. Find the acceleration. ($g = 10$ m/s²) $F_{net} = F_1 + F_2 – f_k$ Step 1:…
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HC Verma Chapter 6 Problem 13 — Ladder against smooth wall
Problem Statement A uniform ladder of mass 10 kg and length 4 m leans against a smooth wall making 60° with the floor ($\mu_s = 0.4$ at floor). Does the ladder slip? ($g = 10$ m/s²) Given Information All quantities, constants, and constraints stated in the problem above Physical constants used as needed (see Concepts…
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HC Verma Chapter 6 Problem 14 — Rolling resistance vs sliding friction
Problem Statement Analyze the circuit: Explain why rolling friction is much smaller than sliding (kinetic) friction. Give a practical example. Rolling friction: deformation of contact area is small; sliding friction: full surface contact with interlocking Step 1: In sliding, asperities (microscopic irregularities) on both surfaces interl Given Information Resistance values $R_1, R_2, \ldots$ as specified…
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HC Verma Chapter 6 Problem 12 — Friction on incline: block at rest
Problem Statement Solve the Newton’s Laws / mechanics problem: A 6 kg block is on a 20° incline. $\mu_s = 0.4$. Find the friction force. ($g = 10$ m/s², $\sin20°=0.342$, $\cos20°=0.940$) Block at rest: friction = $mg\sin\theta$ (static friction provides equilibrium) Step 1: Required friction = $mg\sin20° = 60 \times 0.342 = 20.5$ N. Step…
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HC Verma Chapter 6 Problem 11 — Block on block: slip condition
Problem Statement In Problem 10 setup, if $F = 30$ N, find the acceleration of each block and the friction between them. ($\mu_k = 0.2$ between blocks) Given Information All quantities, constants, and constraints stated in the problem above Physical constants used as needed (see Concepts section) Physical Concepts & Formulas This problem draws on…
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HC Verma Chapter 6 Problem 10 — Block on block: friction between surfaces
Problem Statement Solve the Newton’s Laws / mechanics problem: A 3 kg block rests on a 5 kg block on a frictionless table. $\mu_s = 0.3$ between blocks. A 16 N force is applied on the bottom block. Do the blocks move together? ($g = 10$ m/s²) Check if friction can provide required acceleration to…
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HC Verma Chapter 6 Problem 9 — Stopping distance on rough road
Problem Statement A car moving at 20 m/s brakes. $\mu_k = 0.5$. Find the stopping distance. ($g = 10$ m/s²) Given Information All quantities, constants, and constraints stated in the problem above Physical constants used as needed (see Concepts section) Physical Concepts & Formulas This problem draws on fundamental physical principles. The key is to…
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HC Verma Chapter 6 Problem 8 — Optimal angle to pull a block
Problem Statement A block of mass $m$ on a horizontal surface ($\mu_k$) is pulled by a force $F$ at angle $\theta$ above horizontal. Find $\theta$ that minimizes the required force $F$. Given Information All quantities, constants, and constraints stated in the problem above Physical constants used as needed (see Concepts section) Physical Concepts & Formulas…
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HC Verma Chapter 6 Problem 7 — Force to push block up rough incline at constant speed
Problem Statement Solve the Newton’s Laws / mechanics problem: Find the force required to push a 5 kg block up a 30° rough incline ($\mu_k = 0.2$) at constant speed. ($g = 10$ m/s²) Constant speed → $F = mg\sin\theta + \mu_k mg\cos\theta = mg(\sin\theta + \mu_k\cos\theta)$ Step 1: $F = 5 \times 10(\sin30° +…
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HC Verma Chapter 6 Problem 6 — Block sliding down rough incline: acceleration
Problem Statement Solve the Newton’s Laws / mechanics problem: A 4 kg block slides down a 45° rough incline with $\mu_k = 0.3$. Find the acceleration. ($g = 10$ m/s²) $a = g(\sin\theta – \mu_k\cos\theta)$ Step 1: $a = 10(\sin45° – 0.3\cos45°) = 10 \times \frac{1}{\sqrt{2}}(1-0.3) = \frac{10 \times 0.7}{\sqrt{2}} = \frac{7}{\sqrt{2}} \approx 4.95$ m/s².…