Question

Minimum velocity of a projectile is 20 m/s when a body is projected at an angle of 60 degree with the horizontal .Find the vel of projection....20 m/s,10 m/s,30 m/s or 40 m/s?

Answer 1

so you want the horizontal velocity?

Answer 2

The question i have posted verbatim from my daughter's weekly test. I am not sure but there must be some conditionalities for 20 m/s to be the minimum velocity ..

Answer 3

and there is no diagram or anything?

Answer 4

No none. Only 4 options as I noted above.

Answer 5

it doesnt even have the word "the" at the start of the sentence? Perhaps she copied the question down wrong?

Answer 6

My mistake it should read "The Minimum.. I have the question paper right in front of me..

Answer 7

and it just gives "find the vel of projection"?

Answer 8

It reads " The Minimum.....with the horizontal. The velocity of projection is
1) 20 m/s 2) 10 m/s 3) 30 m/s 4) 40 m/s "

Answer 9

RIGHTTT thats much better. so the minimum velocity is 20m/s in the horizontal direction. find the absolute velocity. okay so i think it looks like this

Answer 10

your trying to find the hypotenuse

Answer 11

yes, that gives an answer which is one of your possible answers

Answer 12

Her text book says there is a minimum velocity of projection to reach a specific point .I am not very satisfied taking 20 m/s as the vel in the horizontal direction. It should have been 20 Cos 60 as the horizontal component as it remains constant..is there any other possibility?

Answer 13

wel in this isntance ? = 40 m/s

Answer 14

what is the specific point?

Answer 15

How did you deduce? Pl help as I need to understand & then teach my daughter.

Answer 16

Well I just found the hypotenuse of that triangle

\[velocity = hypotenuse = \frac{20 m /s}{\cos (60)} = 40 m/s\]