Download App

Motion in a Straight Line — Physics STD 11 Science — Question

Rajasthan BoardEnglish MediumSTD 11 SciencePhysicsMotion in a Straight Line5 Marks
Question
A car starting from rest, accelerates uniformly with 5m/s2 for sometime and then decelerates to come to rest with 3m/s2. Find the maximum velocity attained during the motion and the distance covered in a total time of 6 seconds of the journey.
✓

Answer

During acceleration,
$\text{v}_\text{m}=0+5\times\text{t}_\text{a}$
$\Rightarrow \text{t}_\text{a}=\frac{\text{v}_\text{m}}{5}$
$\text{v}^2_\text{m}=0+2\times5\times\text{s}_\text{a}$
$\Rightarrow \text{s}_\text{a}=\frac{\text{v}^2_\text{m}}{10}$

During deceleration,
$0=\text{v}_\text{m}-3\text{t}_\text{d}$
$\Rightarrow \text{t}_\text{d}=\frac{\text{v}_\text{m}}{3}$
$0=\text{v}^2_\text{m}-2\times3\times\text{s}_\text{d}$
$\Rightarrow \text{s}_\text{d}=\frac{\text{v}^2_\text{m}}{6}$
Total time $=6=\text{t}_\text{a}+\text{t}_\text{d}$
$\therefore \text{v}_\text{m}=\frac{6\times5\times3}{8}=11.25\text{ms}^{-1}$
Total length covered $=\text{s}_\text{a}+\text{s}_\text{d}=\text{v}^2_\text{m}\Big(\frac{1}{10}+\frac{1}{6}\Big)$
$=(11.25)^2\frac{16}{60}$
$=33.75\text{m}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "5 Marks Questions" from Motion in a Straight Line→Motion in a Straight Line — all question types→Physics STD 11 Science question papers→Rajasthan Board STD 11 Science question papers→Rajasthan Board question paper generator→

Similar questions

A particle of mass m is projected from origin O with speed u at an angle with positive x-axis. Find the angular momentum of particle at any time t about O before the particle strikes the ground again.
→
What is the density of water at a depth where pressure is 80.0 atm, given that its density at the surface is 1.03 × 103kg m-3?
→
What is Bernoulli's theory for horizontal tube?
→
A regular polygon of n sides is formed by bending a wire of total length $27\pi\text{r}$ which carries a current i.
  1. Find the magnetic field B at the centre of the polygon.
  2. By letting $\text{n}\rightarrow\infty,$ deduce the expression for the magnetic field at the centre of a circular current.
→
What is a mess pendulum? Discuss its motion for small angular displacement. Deduce the formula for period. On which quantities does the periodic period depend?
→
At what temperature is the root mean square speed of an atom in an argon gas cylinder equal to the rms speed of a helium gas atom at-20°C? (atomic mass of Ar = 39.9u, of He = 4.0u).
→
Given in are examples of some potential energy functions in one dimension. The total energy of the particle is indicated by a cross on the ordinate axis. In each case, specify the regions, if any, in which the particle cannot be found for the given energy. Also, indicate the minimum total energy the particle must have in each case. Think of simple physical contexts for which these potential energy shapes are relevan.

→
The displacement x (in cm) of an oscillating particle varies with time t (in seconds) according to the equation. $\text{x}=2\cos(0.5\pi\text{t}+\frac{\pi}{3})$ Find 
  1. Amplitude of oscillation.
  2. The time period of oscillation.
  3. The maximum velocity of the particle.
  4. The maximum acceleration of the particle.
→
Einstein’s mass - energy relation emerging out of his famous theory of relativity relates mass (m) to energy (E) as E = mc2, where c is speed of light in vacuum. At the nuclear level, the magnitudes of energy are very small. The energy at nuclear level is usually measured in MeV, where 1MeV = 1.6 × 10-13J; the masses are measured in unified atomic mass unit (u) where 1u = 1.67 × 10-27kg.
  1. Show that the energy equivalent of 1u is 931.5MeV.
  2. A student writes the relation as 1u = 931.5MeV. The teacher points out that the relation is dimensionally incorrect. Write the correct relation.
→
Define thermal conduction. Write a relation for rate of flow of heat energy by conduction. Use it to find the equivalent resistance when two rods are placed in series or parallel.
→