Answer:
<em>a. t = 2.02 s
</em>
<em>b. d = 20.2 m</em>
Explanation:
<u>Horizontal Motion
</u>
If an object is thrown horizontally from a height h with a speed v, it describes a curved path ruled exclusively by gravity until it eventually hits the ground.
The time the object takes to hit the ground can be calculated as follows:
The time does not depend on the initial speed.
The range or maximum horizontal distance traveled by the object can be calculated by the equation:
The man standing on the edge of the h=20 m cliff throws a rock with an initial horizontal speed of v=10 m/s.
a.
The time taken by the rock to reach the ground is:
t = 2.02 s
b.
The range is:
d = 20.2 m
<span>The correct answer is B. The law of conservation of mass states that the mass of an isolated system is neither created nor destroy by chemical reaction or physical transformation. This means that the mass of subtances in an isolated system remains constant, it can not decrease and it can not increase.</span>
The correct answer is - A. Plants store solar energy; the plants die; the plants are compressed; solar energy is released;
The plants use the solar energy for their functioning, thus they are one of the biggest natural storage of it. The plants also use the CO2 for the process of photosynthesis that is driven by the solar energy. When the plants die, the things inside them are stored in them, and if they are quickly covered they will remain stored and not get back into the atmosphere. The plants than are compressed, and over time that leads to a change in their composition. After millions of years had passed, the solar energy and CO2 had turned into coal. The coal is heavily used by the humans in the past few centuries, and with its burning the solar energy and the CO2 are released back into the atmosphere from which they came millions of years ago.
The height of the ball when lifted is given by 7sin(25)=2.96
the gravitational energy is mgh, the kinetic is (1/2)mv². We can set these equal since the pendulum doesn't lose much energy
mgh = (1/2)mv²
we can divide by m (since we don't have it anyways)
gh = v²/2
v=√(gh/2) = √(9.81*2.96/2)=3.8m/s.
Not exactly one of your choices, but the right one none the less
Answer:
The length of the rod for the condition on the question to be met is 
Explanation:
The Diagram for this question is gotten from the first uploaded image
From the question we are told that
The mass of the rod is 
The mass of each small bodies is 
The moment of inertia of the three-body system with respect to the described axis is 
The length of the rod is L
Generally the moment of inertia of this three-body system with respect to the described axis can be mathematically represented as
Where 
is the moment of inertia of the rod about the describe axis which is mathematically represented as
And 
the moment of inertia of the two small bodies which (from the diagram can be assumed as two small spheres) can be mathematically represented as
![I_m = m * [\frac{L} {2} ]^2 = m* \frac{L^2}{4}](https://tex.z-dn.net/?f=I_m%20%20%3D%20%20%20m%20%2A%20%5B%5Cfrac%7BL%7D%20%7B2%7D%20%5D%5E2%20%3D%20%20m%2A%20%20%5Cfrac%7BL%5E2%7D%7B4%7D)
Thus 
Hence
=> ![I = [\frac{M}{12} + \frac{m}{2}] L^2](https://tex.z-dn.net/?f=I%20%20%3D%20%20%20%20%5B%5Cfrac%7BM%7D%7B12%7D%20%20%2B%20%5Cfrac%7Bm%7D%7B2%7D%5D%20L%5E2)
substituting vales we have
![0.929 = [\frac{3.41}{12} + \frac{0.249}{2}] L^2](https://tex.z-dn.net/?f=0.929%20%20%20%3D%20%20%20%20%5B%5Cfrac%7B3.41%7D%7B12%7D%20%20%2B%20%5Cfrac%7B0.249%7D%7B2%7D%5D%20L%5E2)
