21.4k views
5 votes
A ball is thrown at 25 m/s making an angle of 50° over a horizontal line. in which instant it velocity will make an 30° angle over a horizontal line?

1 Answer

0 votes

Answer:

0.68 sec

Step-by-step explanation:

let the velocity be "v" when the angle is 30° .

Consider the motion along the horizontal direction


v_(ox) = initial velocity of ball along horizontal direction = 25 Cos50

= 16.07 m/s


v_(fx) = final velocity of ball along horizontal direction = v Cos30

we know that along the horizontal direction


v_(fx) =
v_(ox)

v Cos30 = 16.07

v = 18.56 m/s

Consider the motion along the vertical direction


v_(oy) = initial velocity of ball along vertical direction = 25 Sin50

= 19.2 m/s


v_(fy) = final velocity of ball along vertical direction = v Sin30 = 25 Sin30 = 12.5 m/s


a_(y) = acceleration = - 9.8 m/s²


t = time taken

using the equation


v_(fy) = v_(oy) + a_(y) t

12.5 = 19.2 + (- 9.8) t

t = 0.68 sec

User Manish Gupta
by
6.2k points