Question

a projectile is fired at 30 degree to the horizontal the vertical component of velocity is 20 m per second .its time of flight is T. what will be the velocity of projectile at time t is equal to T upon 2

Answer 1

UsinA=20 m/s

SinA=30°=1/2

U=40m/s

Now T=2usinA/g

T=2×40×.5/10. Taking g=10m/s^2

We get T =4 sec

For T=T/2

4/2= 2USinA/g

2=2×U×.5/g new velocity =U at T/2

We get U =20m/s

Answer 2

Formula:

Time of flight = (2uSin Ф) / g

u = initial velocity

g = acceleration due to gravity.

Ф = angle of projection.

take g = 10

Doing the substitution we have :

Time of flight = ( 2 × 20 × Sin 30) / 10

= 20/10 = 2

Time of flight = 2 seconds .