Start learning →

Indian Navy Pilot Work and Energy — practice questions

Explore 51 free Work and Energy questions in Indian Navy Pilot Physics. Open each question or exercise to read its content, reference answers and available explanation.

Practise Work and Energy with Quill →

Work and Energy questions and exercises with answers

Showing questions 1–30 of 51.

The elastic potential energy stored in a spring of spring constant $k$ when stretched by displacement $x$ is:Read the answer and worked solution →The work-energy theorem states that the net work done on a body equals:Read the answer and worked solution →Newton's FIRST law is also called the law of:Read the answer and worked solution →The SI unit of force is the:Read the answer and worked solution →A block of mass 2 kg on a smooth incline at 30°. Acceleration down the incline (g = 10):Read the answer and worked solution →A pendulum of mass m swings to amplitude angle θ. At the lowest point of swing, the TENSION in the string equals:Read the answer and worked solution →As per your syllabus, Newton's SECOND law in SI units states which relation?Read the answer and worked solution →As per your syllabus, the IMPULSE J of a force F acting for time Δt equals which quantity?Read the answer and worked solution →As per your syllabus, KINETIC (sliding) friction is approximately given by which relation?Read the answer and worked solution →As per your syllabus, the coefficients of static and kinetic friction satisfy which order?Read the answer and worked solution →As per your syllabus, A · B equals which expression?Read the answer and worked solution →As per your syllabus, work done by a force perpendicular to the displacement (e.g. centripetal force in UCM) is which?Read the answer and worked solution →As per your syllabus, the work done by a VARIABLE force F(x) over displacement from x_i to x_f is which?Read the answer and worked solution →As per your syllabus, INSTANTANEOUS power is given by which expression in terms of F and v?Read the answer and worked solution →As per your syllabus, 1 horsepower (hp) is approximately equal to which value?Read the answer and worked solution →As per your syllabus, an ELASTIC collision conserves which two quantities?Read the answer and worked solution →True or false: what Aristotle got wrongRead the answer and worked solution →Complete Newton's first lawRead the answer and worked solution →Which law is this?Read the answer and worked solution →MomentumRead the answer and worked solution →True or false: inertia and forceRead the answer and worked solution →Assertion and reasonRead the answer and worked solution →Two are true, one is notRead the answer and worked solution →Three of these are wrong. Find the one that holds.Read the answer and worked solution →Tap every statement the first law licensesRead the answer and worked solution →Flip and pair: name with contributionRead the answer and worked solution →Spot the one that does not belongRead the answer and worked solution →Order the historical argumentRead the answer and worked solution →Complete the work-energy theoremRead the answer and worked solution →True or false: conservative forcesRead the answer and worked solution →

Worked practice questions

The elastic potential energy stored in a spring of spring constant $k$ when stretched by displacement $x$ is:

  1. $kx$
  2. $\dfrac{1}{2} k x^2$
  3. $k x^2$
  4. $\dfrac{1}{2} k^2 x$
Show answer and solution

Correct answer: B. $\dfrac{1}{2} k x^2$

Force needed to stretch a spring by $x$ is $F = kx$ (Hooke's law). Work done in stretching from 0 to $x$: $U = \int_0^x kx' \, dx' = \dfrac{1}{2} k x^2$. The $\tfrac{1}{2}$ shows up because force grows linearly during the stretch — average force is $kx/2$, total work is $kx/2 \cdot x = \tfrac{1}{2} k x^2$. Option A ($kx$) is the *force*, not the energy.

Open this question →

The work-energy theorem states that the net work done on a body equals:

  1. The change in its kinetic energy
  2. The change in its potential energy
  3. The total mechanical energy
  4. The momentum of the body
Show answer and solution

Correct answer: A. The change in its kinetic energy

Work-energy theorem: $W_{\text{net}} = \Delta KE = KE_{\text{final}} - KE_{\text{initial}}$. This is a direct consequence of Newton's second law. Apply $F = ma$ and integrate over displacement: $\int F \, dx = \int m a \, dx = \int m v \, dv = \tfrac{1}{2} m v^2 \big|_{u}^{v} = \Delta KE$. If only conservative forces act, this is equivalent to saying $\Delta KE + \Delta PE = 0$, the conservation of mechanical energy. With friction or other dissipative forces present, energy is lost to heat and the strict mechanical-energy conservation breaks, but the work-energy theorem still holds because work includes *all* forces.

Open this question →

Newton's FIRST law is also called the law of:

  1. Inertia
  2. Action and reaction
  3. Gravity
  4. Friction
Show answer and solution

Correct answer: A. Inertia

Law of Inertia: An object at rest stays at rest, and an object in motion stays in motion at constant velocity, unless acted upon by an unbalanced external force.

Open this question →

How to practise

  1. Choose a Work and Energy question and try to work out your answer.
  2. Open the question to check the correct answer and read its worked solution.
  3. Continue in the app for bite-sized lessons, explanations and review with Quill. You can start without creating an account.

More Physics topics

Physics and MeasurementWork and PowerOpticsCurrent ElectricityC9kineticenergyEnergy Transfer in SystemsPotential and Kinetic EnergyRay and Wave Optics