How Long Until a Thrown Ball Hits the Ground?

[manal950]

A small steel ball is hot vertically upward from vertically upward from the top of a building 25 above the ground with an initial velocity of 18 m/s .
1 ) In what time it will reach the ground ?
2 ) compute the velocity with which it will strike the ground and the total time it is in the motion

please I want know What is the difference between time it will reach the ground and total time

Is same or what

 

[Villyer]

They look like the same in these questions.

 

[manal950]

but I have the answer for this Q :

t = 1.83 s
V 28.5
t2 = 2.9 s
total = 4.7s

now what is the difference between t and total

 

[Villyer]

The 1.83 is the time that this ball takes to reach the top of its path.
Is that what the book gives as the answer to part a?

 

[manal950]

This is full Q
A small steel ball is hot vertically upward from vertically upward from the top of a building 25 above the ground with an initial velocity of 18 m/s .
1 ) In what time it will reach the ground ?
2) how high above the building with the ball rise
2 ) compute the velocity with which it will strike the ground and the total time it is in the motion and the answer
t1 = 183
h1 = 16.52
v = 28.5
t2 = 2.9
Total time = 4.37

 

[azizlwl]

You should try to answer the question.
After getting your answer, then only you compare with the answer given.

You shouldn't looking at the answer first and try to reverse the process.
Everybody makes mistakes. Thats how we learn. Don't try to prove the answers in the book. They are nearly all correct, except maybe typo.

 

[manal950]

Hi I know how to solve this Q but there is confusing at some point

 

[azizlwl]

You know the answers but not the workings.

 

[Villyer]

Their t1 is the time it takes for the ball to reach h1.

So it's possible that the question was reworded at some point and the answer wasn't changed.