What maximum height a stone will reach it is thrown upward with a velocity of 20 Metre per second?

A stone is thrown vertically upwards with a speed of 20 m/s. How high will it go before it begins to fall ? (g =9.8 m/s2)

s (distance) = ?v (final velocity) = 0 m/s

u (initial velocity) = −20 m/s

The negative sign comes because the displacement is upward and we have considered the motion along the acceleration due to gravity (downward) as positive. Thus, the required distance is 20.4 m.

Concept: Mass and Weight of an Object

  Is there an error in this question or solution?

Free

10 Questions 10 Marks 10 Mins

CONCEPT:

• Equation of motion: Equations of motion relate the displacement of an object with its velocity, acceleration, and time.
  • The motion of an object can follow many different paths. Here the motion is in a straight line (one dimension). 
• When the body is displaced with negative acceleration. 

​ v = u + at

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

CALCULATION:

Given:

 v = 0 (since the velocity will become zero at the highest point)

u = 60m/s

a = -10m/s (acceleration due to gravity and "-" sign for the opposite direction. 

using the the formula:

 v = u + at

0 = 60 -10t

 t = 6 sec.

• Now we know after t = 6 sec the ball will be at the highest point.

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

\(s = 60 \times 6 + \frac{1}{2}\times -10\times 6 \times 6\)

\(s = 180m\)

• The maximum height attained by the particle will be 180m.
• Hence option 4 is the answer.

Stay updated with the Physics questions & answers with Testbook. Know more about Motion in a Straight Line and ace the concept of Kinematic equations for uniformly accelerated motion.

India’s #1 Learning Platform

Start Complete Exam Preparation

Daily Live MasterClasses

Practice Question Bank

Mock Tests & Quizzes

Get Started for Free Download App

Trusted by 3.3 Crore+ Students