Question

A projectile is fried at an angle of 30 degree to the
horizontal such that the vertical compounds of its
initial velocity is 80m/s . Its time of flight is T. Its
velocity at t is
$\frac{t}{4}$
has a
magnitude of nearly?​

Answer 1

QUESTION :

• A projectile is fried at an angle of 30 degree to the horizontal such that the vertical compounds of its initial velocity is 80m/s . Its time of flight is T. Its velocity at t is t /4 has a magnitude of nearly?

GIVEN :

• angle of projection = 30°
• vertical component of initial velocity (u y)= 80 m /s ( along y - axis )

SOLUTION :

Time of flight is given as T

T = 2 u sin x / g

we know that ,

u y = u sin x = 80 m /s

T = 2 × 80 / 10

T = 16 sec

T / 4 = 16 / 4 = 2 sec

Initial velocity :

vertical component

u y = u sin x = 80

u sin 30 = 80

u = 160 m / s

horizontal component

u x = u cos 30 = 160 × √ 3 / 2 = 80√3

Final velocity ( t = 2 sec ) :

horizontal component

u x = v x = 80√ 3

vertical component

v y = u y - g t

v y = 80 - 10 ×2

v y = 80 -20

v y = 60 m / s

v = √ v x ² + v y ²

v = √ ( 80√3)² + ( 60)²

v = √ 19200+3600

v = √22800

v = 150 m / s