<h2>Answer: 10.52m</h2><h2 />
First, we have to establish the <u>reference system</u>. Let's assume that the building is on the negative y-axis and that the brick was thrown at the origin (see figure attached).
According to this, the initial velocity
has two components, because the brick was thrown at an angle
:
(1)
(2)
(3)
(4)
As this is a projectile motion, we have two principal equations related:
<h2>
In the x-axis:
</h2>
(5)
Where:
is the distance where the brick landed
is the time in seconds
If we already know
and
, we have to find the time (we will need it for the following equation):
(6)
(7)
<h2>
In the y-axis:
</h2>
(8)
Where:
is the height of the building (<u>in this case it has a negative sign because of the reference system we chose)</u>
is the acceleration due gravity
Substituting the known values, including the time we found on equation (7) in equation (8), we will find the height of the building:
(9)
(10)
Multiplying by -1 each side of the equation:
>>>>This is the height of the building
-- The truck begins the scenario moving at 6 m/s.
-- After increasing its speed at the rate of 2 m/s² for 12 seconds,
it has gained (2 x 12) = 24 m/s of speed, and it's then moving
at 30 m/s.
-- The truck's average speed during the 12 seconds is (1/2) (6 + 30) = 18 m/s
-- Traveling at an average speed of 18 m/s for 12 seconds,
the truck travels
(18 m/s) x (12 sec) = 216 meters
Answer:
2.087 kg
Explanation:
From the law of conservation of momentum,
Total momentum before collision = total momentum after collision.
MU + mu = V(M+m)............................ Equation 1
Where M = mass of the cart, m = mass of the brick, U = initial velocity of the cart, u = initial velocity of the brick, V = velocity of both cart and brick after collision.
Note: The initial velocity of the brick is zero Thus mu = 0
making m the subject of the equation,
m =(MU/V)-M ........................................ Equation 2
Given: M = 2.6 kg, U = 28.2 cm/s = 0.283 m/s, V = 15.7 cm/s = 0.157 m/s.
Substituting into equation 2,
m = (2.6×0.283/0.157)-2.6
m = 2.087 kg
Thus the mass of the brick = 2.087 kg
A "live" wire or "hot" wire is one that's energized. <em>(B)</em>
It doesn't matter whether it has electrical current flowing in it or not. If the live, hot, energized conductor has <u><em>voltage</em></u> on it, there is risk of being shocked if you come in contact with it.
Answer:
D
Explanation:
At noon on the summer solstice. The sun dagger was used to observe astrological readings in the ancient time