Asteel projectile is shot horizontally at 20m/s from the top of a 40m tower. how long does it take to hit the ground? how far from the base of the tower does the projectile hit the ground

1) 2.86 s

To find the time of flight, we have to analyze the vertical motion of the stone, which is a uniformly accelerated motion (free fall) with constant acceleration (acceleration of gravity).

The vertical displacement at time t is given by

where , taking downward as positive direction

is the initial vertical velocity  (which is zero, since the projectile is shot horizontally)

t is the time

is the acceleration of gravity

In this problem we have

s = 40 m (vertical displacement is the height of the tower)

Solving for t, we find the time of flight: of the projectile:

So, the projectile takes 2.86 s to hit the ground.

2) 57.2 m

The horizontal motion of the projectile is a uniform motion: in fact there are no forces acting on the projectile along the horizontal direction, so the horizontal acceleration is zero, and so the horizontal velocity is constant.

The initial horizontal velocity of the projectile is

Therefore, to find the horizontal distance covered by the projectile, we can just use the equation

And substitute the time of flight, which is the time at which the projectile hits the ground:

t = 2.86 s

So, we get:

  the grams     of oxygen gas   that can be produced     is 20.6   grams of o₂

calculation

2liclo₃ →   2 licl + 3 o₂

step 1:   find the moles of liclo₃

moles = mass÷ molar mass

from periodic table the molar mass of liclo₃ =6.9 +35.5   +(16 x3) =90.4 g/mol

moles=38.7 g÷90.4 g/mol=0.4281   moles

step 2:   use the   mole ratio   to calculate the moles of o2

from equation above, liclo₃: o₂   is 2: 3  

therefore the moles of   o₂=0.4281 moles x3/2 =0.6422   moles

step 3: find mass   of o₂

mass= moles x molar mass

from periodic table the   molar mass of   o₂ = 16 x2= 32 g/mol

mass=0.6422   moles   x   32 g/mol = 20.6 grams of o₂

where is the photo and the answer choices?