Download App

3.2 , motion in plane — Physics STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 SciencePhysics3.2 , motion in plane1 Mark
MCQ
A girl standing at point $P$ on a beach wishes to reach a point $Q$ in the sea as quickly as possible. She can run at $6 \,kmh ^{-1}$ on the beach and swim at $4 \,kmh ^{-1}$ in the sea. She should take the path
  • A
    $P A Q$
  • B
    $P B Q$
  • ✓
    $P C Q$
  • D
    $P D Q$
✓

Answer

Correct option: C.
$P C Q$
c
(c)

To reach point $Q$, using Fermat's principle, girl must bend her path towards normal as on beach velocity of girl is more than her velocity at sea.

So, correct path is $P C Q$ to reach in shortest time.

Note Laws of refraction of light follows from Fermat's principle.

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 "M.C.Q (1 Marks)" from 3.2 , motion in plane→3.2 , motion in plane — all question types→Physics STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

The time in which a force of $2 \,N$ produces a change of momentum of $0.4\,kg - m{s^{ - 1}}$ in the body is ......... $\sec$
→
The permanent magnetic moment of the atoms of a material is not zero. The material:
→
A monkey is decending from the branch of a tree with constant acceleration. If the breaking strength is $75 \%$ of the weight of the monkey, the minimum acceleration with which monkey can slide down without breaking the branch
→
The coordinates of centre of mass of a uniform flag shaped lamina (thin flat plate) of mass $4\;kg$. (The coordinates of the same are shown in figure) are
→
If the breaking force for a given wire is $F$, If the thickness of the wire is doubled, then the breaking force will be
→
In a bicycle the radius of rear wheel is twice the radius of front wheel.  If  ${r_F}$ and ${r_r}$ are the radii, $v_F$ and $v_r$ are speeds of top most points of wheel, then      
→
A transverse wave travels along the Z-axis. The particles of the medium must move:
→
A wheel of moment of inertia $10\ kg-m^2$ is rotating at $10$ rotations per minute. The work done in increasing its speed to $5$ times its initial value, will be.......... $J$
→
Which of the following statements is correct in respect of a geostationary satellite
→
Three simple harmonic motions in the same direction having the same amplitude a and same period are superposed. If each differs in phase from the next by ${45^o}$, then
→