Easy & Concise NCERT Physics Ch-4 & 5 : All Exercises Solved

Analyze a 0.40 kg body with 10 m/s north speed under an 8 N south force for 30 s, yielding 20 m/s^2 and final positions and velocity using kinematic equations.

Describe the stone's projectile motion after dropping from a truck accelerating at 2.0 m/s^2, with horizontal 20 m/s and vertical gravity 10 m/s^2, giving 22.4 m/s at 11 s.

Apply impulse and momentum to find gun recoil: a 0.020 kg shell at 80 m/s transfers 1.600 N.s to a 100 kg gun, yielding 0.016 m/s recoil.

Analyze how applied work transfers energy to a bucket while gravity and friction do negative work, yielding zero total work and unchanged kinetic energy in pendulum motion.

Explore how total energy equals potential plus kinetic energy, compute the potential at x = ±2 m, and show kinetic energy vanishes at maxima, limiting the particle to 2 m.

Explain work energy and momentum concepts: conservative forces change potential energy, friction reduces kinetic energy, and external forces alter momentum; total momentum and energy remain conserved in collisions.

Explain the differences between elastic and inelastic collisions, demonstrating how momentum is conserved in the short collision interval and how kinetic energy converts to potential energy in elastic cases.

In one-dimensional motion from rest with constant acceleration, distance is s = 1/2 a t^2. Work equals m a s, so power equals (1/2) m a^2 t, proportional to time.

Under constant power, a body moves unidirectionally with displacement proportional to t^{3/2}; velocity is v = sqrt(2Pt/m) and displacement x = (2/3)(2Pt/m)^{3/2}, showing x ∝ t^{3/2}.

Compute the work as the dot product of the constant force F = -i + 2j + 3k N with the displacement 4 m along the z-axis, yielding 12 joules.