- Home
- Standard 11
- Physics
3-2.Motion in Plane
normal
Two cars $S_1$ and $S_2$ are moving in coplanar concentric circular tracks in the opposite sense with the periods of revolution $3 \,min$ and $24 \,min$, respectively. At time $t=0$, the cars are farthest apart. Then, the two cars will be
Aclosest to each other at $t=12 \,min$ and farthest at $t=18 \,min$
Bclosest to each other at $t=3 \,min$ and farthest at $t=24 \,min$
Cclosest to each other at $t=6 \,min$ and farthest at $t=12 \,min$
Dclosest to each other at $t=12 \,min$ and farthest at $t=24 \,min$
(KVPY-2017)
Solution
(D)At $t=12 \,min$, car $S_1$ has completed three rounds and it is at its position.
At $t=12 \,min$, car $S_2$ completed half round and it is at diametrically opposite point as shown below.
So, cars are closest at $t=12 \,min$.
At $t=24 \,min$, cars $S_1$ and $S_2$ are both at their initial positions and so are farthest, as shown below.
Hence, cars are farthest from each other at $t=24 \,min .$
Standard 11
Physics
