Question

A stone is thrown vertically upward with a speed of 50 m/s. The magnitude of its displacement after 5 s will be ________.(Take g = 10 m/s2)

1. 150 m
2. 125 m
3. 140 m
4. 130 m

Answer 1

Correct Answer - Option 2 : 125 m

The correct answer is 125 m.

Concept:

In Classical physics, we can predict the motion of the particles using the kinematic equation

And according to the kinematic equation

1. v = u + at
2. v2 = u2 + 2as
3. s =ut + ½ at2

Calculation:

Given,

Initial Velocity (u) = 50 m/s.

Acceleration due to gravity (g) = -10 m/s2 (-ve because of Upward motion).

Time (t) = 5 Seconds.

Using the equation:

\(s= ut +{1 \over 2} at^2\)

⇒ s = 50 × 5 + 1/2 × (-10) × 5²

⇒ s = 250 + 1/2 × (-10) × 25

⇒ s = 250 - 125 = 125 m