JEE Physics Question: Harmony of 3D Projectiles
JEE Physics Question: Harmony of 3D Projectiles
JEE Physics Question: Harmony of 3D Projectiles
Q.27
A large disc has its center hinged to the ground about which it rotates with a constant angular speed. A small
car fitted with a gun is fixed at the periphery of the disc (fig 27.1, 27.2). Points A and B are marked in the
figure for reference.
The gun always faces the central axis of rotation and the size of the gun is set such that, when inclined, it
prevents anything from getting into the car. The gun harmonically changes its angles of inclination with
horizontal (rising out of the horizontal plane) with upper and lower bounds of 𝜋/2 and 0 radians respectively.
It opens up every time near A with a period equal to that of the rotation of the disc. Mass of the car and gun
is negligible relative to the disc, mass of the bullet is 1 kg and that of the disc is 20 kg.
When the car crosses B for the third time, a bullet is fired.