Answer:
<em>t=14.96 sec</em>
Explanation:
<u>Diagonal Launch
</u>
It's a physical event that happens where an object is thrown in free air (no friction) forming an angle with the horizontal reference. The object then describes a path called a parabola.
The object will reach its maximum height and then return to the height from which it was launched. The equation for the height is
:
Where vo is the initial speed, is the angle, t is the time and g is the acceleration of gravity
.
In this problem we'll assume the arrow was launched from the ground level (won't consider the archer's height). Thus , and:
The value of y is zero twice: when t=0 (at launching time) and in t= when it goes back to the ground. We need to find that time by making
Dividing by
Then we find the total flight time as
According to Newton's Second Law of Motion, the force is directly proportional to mass and acceleration. However, mass and acceleration are inversely proportional to each other. It is best interpreted by the equation: F = ma. So, for the same amount of force, it would produce less acceleration on the greater mass of the helicopter.
Answer:
The cell theory
Explanation:
The explanation of the relationship between the building blocks of life based on the evidence gathered by scientists from studying these building blocks is called <u>the cell theory.</u>
Many scientists study the building blocks. One of the earliest scientists to study these blocks gave them the name 'cells'. Thereafter, several other scientists studied different aspects of the cell and, eventually, the cell theory was propounded. There are three aspects to the theory:
- <em>All living organisms are made up of cells.</em>
- <em>The cell is the basic unit of life.</em>
- <em>Cells arose from preexisting cells by cell division.</em>
Question:
Calculate the change in internal energy of the following system: A balloon is cooled by removing 0.652 kJ of heat. It shrinks on cooling, and the atmosphere does 389 J of work on the balloon. Express your answer in Joules (J)
Answer:
-263J
Explanation:
Though its difficult and infact impossible to measure the internal energy of a system, the change in internal energy ΔE, can however be determined. This change when it is accompanied by work(W) and transfer of heat(Q) in or out of the system, can be calculated as follows;
ΔE = Q + W ----------------(i)
Q is negative if heat is lost. It is positive otherwise
W is negative if work is done by the system. It is positive otherwise.
From the question;
Q = -0.652kJ = -652J {the negative sign shows heat loss}
W = +389J {the positive sign shows work done on the system(balloon)}
<em>Substitute these values into equation (i) as follows;</em>
ΔE = -652 + 389
ΔE = -263J
Therefore the change in internal energy is -263J
PS: The negative sign shows that the process is exothermic. This means that the system (balloon) lost some energy to the environment.