Question

:A stone is thrown horizontally from the top of a cliff. Air resistance is negligible. Which graph shows the variation with time of the vertical component of the stone's velocity?
(A)

(B)

(C)
                         

  (D) None of the above

Answer 1

Hint: The stone is thrown horizontally the velocity will increase with variation of time. Initial Velocity is the velocity at time interval t = 0 and it is represented by u. It is the velocity at which the motion starts. They are four initial velocity formulas: (1) If time, acceleration and final velocity are provided.

Solution step by step

Initially velocity of vertical component =0

acceleration due to gravity = g

So, the starting velocity at time t,

\[\begin{array}{*{20}{l}}

  {\;v = u + at} \\

  { \Rightarrow \;\;v = 0 + gt} \\

  {\; \Rightarrow v = gt}

\end{array}\].

It is a straight line equation so the graph is a straight line from starting point 0

Note: The equation is of straight line passing through the origin and of slope g. Where g is gravitational acceleration, gravitational acceleration is the free fall acceleration of an object in vacuum — without any drag. This is the steady gain in speed caused exclusively by the force of gravitational attraction.