<h2>
Answer:</h2>
The reaction is <u>D. endothermic</u>.
<h2>
Explanation:</h2>
Absorption or need of energy from surroundings is called endothermic process. Heat is the major common form of energy which is absorbed in this process. In this process, enthaply of reactant is less than the product.
For example, an ice cube placed in the hand for some time starts to melt and it takes energy in the form of heat from the hand. This process always requires energy because of the breaking of existing and formation of new chemical bonds.
Explanation:
As we know that the maximum of thermal energy will be converted into mechanical energy.( The thermal energy will be given to us by engine.)
But the total thermal energy will not be converted into the mechanical energy, there will be some lost of energy. The lost of mechanical energy will be in multiple forms. 2 of them are
1.Heat : The mechanical energy heats up the engine and then it will lost some energy.
2.Noise : Some energy also lost in the sound or the noise comes out from the engine. It will consume some energy.
Also, the engine never be 100% efficient some amount of energy lost in environment also.
Answer: 2561.7 pounds
Explanation:
If we assume the total weight of an airplane (in pounds units) as a <u>linear function</u> of the amount of fuel in its tank (in gallons) and we make a Weight vs amount of fuel graph, which resulting slope is 5.7, we can use the slope equation of the line:
(1)
Where:
is the slope of the line
is the airplane weight with 51 gallons of fuel in its tank (assuming we chose the Y axis for the airplane weight in the graph)
is the fuel in airplane's tank for a total weigth of 2390.7 pounds (assuming we chose the X axis for the a,ount of fuel in the tank in the graph)
This means we already have one point of the graph, which coordinate is:

Rewritting (1):
(2)
As Y is a function of X:
(3)
Substituting the known values:
(4)
(5)
(6)
Now, evaluating this function when X=81 (talking about the 81 gallons of fuel in the tank):
(7)
(8) This means the weight of the plane when it has 81 gallons of fuel in its tank is 2561.7 pounds.
hiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii
Answer:
d.
Explanation:
Since the dart's initial speed v at angle has both vertical and horizontal components v₀sinθ and v₀cosθ respectively, the vertical component of the speed continues to decrease until it hits the target. It's displacement ,s is gotten from
s = y - y₀ = (v₀sinθ)t - 1/2gt² where y₀ = 0 m
y - 0 = (v₀sinθ)t - 1/2gt²
y = (v₀sinθ)t - 1/2gt²
which is the parabolic equation for the displacement of the dart.
Note that the horizontal component of the dart's velocity does not change during its motion.
Since the target falls vertically, with initial velocity u = 0 (since it was stationary before the string cut), it's displacement ,s' is gotten from
s' = y - y₀' = ut - 1/2gt² where y₀' = initial height of target above the ground
= (0 m/s)t - 1/2gt²
= 0 - 1/2gt²
y - y₀' = - 1/2gt²
y = y₀' - 1/2gt²
which is the parabolic equation for the displacement of the target.
The equation for both the displacement of the dart and the target can only be gotten if we considered vertical motion. So, the displacement component of both the dart and target are both vertical.
So, the answer is d.