A javelin thrown by an athlete is in ________ motion.

Correct — C. A javelin leaves the hand at an angle and is then acted on by gravity alone, so its path bends instead of staying straight.

Motion along a curved path is curvilinear motion — the two-dimensional counterpart of rectilinear motion.

Ignoring air resistance, that curve is the parabola of projectile motion, the standard textbook case of curvilinear motion → option (c).

Why the others are wrong

• (a)
  rectilinear — Rectilinear motion is motion along a straight line — a ball dropped vertically, a train on a straight track. The javelin's path bends, so it fails that test at once.
• (b)
  periodic — Periodic motion repeats at equal intervals, like the hands of a clock or the Earth's revolution. A single throw happens once, so there is no period to speak of.
• (d)
  oscillatory — Oscillatory motion is a to-and-fro movement about a fixed mean position, like a pendulum or a loaded spring. A javelin never returns towards its start, so there is no mean position.

Motion is classified two ways at once, and the two classifications are independent.

By the shape of the path: rectilinear (a straight line), curvilinear (a curve), rotatory (about an axis).

By repetition: periodic motion repeats at equal intervals, and oscillatory motion is the special case that repeats to and fro about a mean position. Oscillatory motion is periodic, but not all periodic motion is oscillatory — the Earth's revolution repeats without going back and forth.

A projectile — a javelin, a shot put, a thrown ball — is the standard curvilinear example.

Key facts

• Curvilinear motion is motion along a curved path.
• A projectile launched at an angle traces a parabola when air resistance is ignored.
• Rectilinear motion is motion along a straight line.
• Oscillatory motion is to-and-fro motion about a mean position and is a special case of periodic motion.

Common traps

• Choosing 'periodic' because sport feels repetitive — one throw repeats nothing.
• Using oscillatory and periodic as interchangeable words.

No directly related past PYQ was found.