Aprojectile is launched horizontally from a height of 8.0 m. the projectile travels 6.5 m before hitting the ground. the velocity of the projectile the moment it was launched, rounded to the nearest hundredth, is m/s.

5.09 m/s

Explanation:

Since the projectile is launched horizontally, there is only a horizontal component of the initial velocity: , which is the unknown. Notice then that the vertical component of the initial velocity is ZERO.

So when studying the vertical motion of the projectile under the action of gravity to find the time it takes to hit the ground, the equation for this accelerated motion becomes:

Since we want to find the time it takes for the projectile to hit the ground, we make the final y-position equal zero:

Now we use the time it takes to hit the ground to estimate the initial horizontal velocity via the equation that describes the horizontal motion (with constant velocity):

Since we know that the projectile travels 6.5m horizontally, we use this equation to solve for :

5 w for 1hr = 5x60x60 joules=300x60=3000x6=18,000j as total energy conversion. efficiency of bulb needed for radiant to thermal within 18000

frequency or wavelenth of em radiation in a vacuum