Question icon
Grade 12Mechanics

A body is fired upward with speed v . It takes time T to reach its maximum heght H.True or False.

a)It reaches H/2 in T/2

b)it has speed v/2 at H/2

c)it has speed v at 2T

Profile image of bhavini garg
15 Years agoGrade 12
Answers icon

2 Answers

Profile image of Sabhareesh R
15 Years ago

C)

It has a speed v at 2T

Profile image of Neel Pratik Bhatt
15 Years ago

To,

The person who Asked the Question:

When a body(an object) is fired up it will always have a negative acceleration or dissileration and will come to a stop.

Basically u represents the intial velocity and v represents the final velocity, but if you are taking v as the speed i.e distance upon time then:

GIVEN:

H is the maximum distance or height

v is the speed with wich the object was travelling

so,

we cannot say that H/2 in T/2 ( time taken to reach ) as you know that its deccelerating and so speed is not constant so v is not constant first of all so at a instant speed may be v1 and at the other it might be v2 . So i would say flase Example:

Lets take H as 5 mts And v is 3 mts.sec^-1then at 2.5 mts you can't say speed will be the same as it will be at 2.9 right?? As at 5 mts speed is 0 and at 2.5 speed may be 2.29. Under stood?

so in the same way v/2 at H/2 is false

Third is also False

 

If you didn't understand please reply as to Make you more clearer!!

Neel