Q. 184.0( 134 Votes )

A ball thrown up

Answer :

Since the ball thrown up vertically returns to the thrower in 6 seconds, this means that the ball will take half of this time.

= 3 s


(a) Given,


Final velocity, v = 0


Initial velocity, u =?


Acceleration due to gravity, g = -9.8 m/s2 (As the ball goes up)


Time taken, t = 3 s


We know that,


v = u + g × t


0 = u + (-9.8) × 3


0 = u – 29.4


u = 29.4 m/s


(b) Now, calculation of maximum height:


We know that, at maximum height velocity of object will be Zero 

v(final velocity at max height)=0 m/s

u(initial velocity)  = 29.4 m/s

g(acceleration due to gravity)=10 m/s2

using third equation of motion , we get

v2 = u2 + 2gh

(0)2 = (29.4)2 + 2 × (-9.8) × h


0 = 864.36 – 19.6 h


19.6 h = 864.36


h =


h = 44.1 m


(c) Finally, we have to calculate the position of ball after 4 seconds:


We know that, the ball will at max height when t=3 sec at t = 4 sec the ball has been falling for 1 sec from the max height  

hence, t= 1 sec

u(initial velocity)=0 m/s

a(acceleration due to gravity) = 9.8 m/s2

h = 0×1+ ×9.8 × (1)2 (Because t = 1 s)

= 0 + 4.9 ×1

= 4.9 m
Hence, ball has been fallen 4.9 m from the max height

The height from the ground= maximum height - height object has fallen in 1 sec= 44.1- 4.9= 39.2 m above the ground


Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Variation in g with Rotation of EarthVariation in g with Rotation of EarthVariation in g with Rotation of Earth42 mins
Questions based on Acceleration due to GravityQuestions based on Acceleration due to GravityQuestions based on Acceleration due to Gravity40 mins
Mastering Kepler's LawMastering Kepler's LawMastering Kepler's Law41 mins
Lets Revise all DerivationsLets Revise all DerivationsLets Revise all Derivations41 mins
Chapter Test on GravitationChapter Test on GravitationChapter Test on Gravitation42 mins
Law of GravitationLaw of GravitationLaw of Gravitation40 mins
Variation in g due to Height and DepthVariation in g due to Height and DepthVariation in g due to Height and Depth33 mins
Satellite MotionSatellite MotionSatellite Motion45 mins
Circular MotionCircular MotionCircular Motion37 mins
Quiz | Kaun Banega  Champion (KBC) GravitationQuiz | Kaun Banega  Champion (KBC) GravitationQuiz | Kaun Banega Champion (KBC) Gravitation33 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
caricature
view all courses
RELATED QUESTIONS :

MathematicaTogether with Science

A bomb is releaseEvergreen - Science

Identical packetsNCERT Science - Exemplar

Two objects of diLakhmir Singh & Manjit Kaur - Physics

State the eTogether with Science

A soft drink bottEvergreen - Science

A ball is thrown Evergreen - Science

A stone is droppeEvergreen - Science