When you're talking about gravity, it's easy to identify the equal
opposite forces.
Gravity ALWAYS produces an equal pair of opposite forces.
They both act between the centers of the two objects, one in
each direction.
Consider the equal pair of opposite gravitational forces between
you and the Earth. One force acts on you, and draws you toward
the center of the Earth. We call that force "your weight".
The other one acts on the Earth, and draws it toward the center
of you. Hardly anybody ever talks about that one, but the two
forces are equal ... your weight on Earth is equal to the Earth's
weight on you !
Answer:
The maximum height attained by the object and the number of seconds are 128 ft and 4 sec.
Explanation:
Given that,
Initial velocity u= 128 ft/sec
Equation of height
....(I)
(a). We need to calculate the maximum height
Firstly we need to calculate the time
![\dfrac{dh}{dt}=0](https://tex.z-dn.net/?f=%5Cdfrac%7Bdh%7D%7Bdt%7D%3D0)
From equation (I)
![\dfrac{dh}{dt}=128-64t](https://tex.z-dn.net/?f=%5Cdfrac%7Bdh%7D%7Bdt%7D%3D128-64t)
![128-64t=0](https://tex.z-dn.net/?f=128-64t%3D0)
![t=\dfrac{128}{64}](https://tex.z-dn.net/?f=t%3D%5Cdfrac%7B128%7D%7B64%7D)
![t=2\ sec](https://tex.z-dn.net/?f=t%3D2%5C%20sec)
Now, for maximum height
Put the value of t in equation (I)
![h =128\times2-32\times4](https://tex.z-dn.net/?f=h%20%3D128%5Ctimes2-32%5Ctimes4)
![h=128\ ft](https://tex.z-dn.net/?f=h%3D128%5C%20ft)
(b). The number of seconds it takes the object to hit the ground.
We know that, when the object reaches ground the height becomes zero
![128t-32t^2=0](https://tex.z-dn.net/?f=128t-32t%5E2%3D0)
![t(128-32t)=0](https://tex.z-dn.net/?f=t%28128-32t%29%3D0)
![128=32t](https://tex.z-dn.net/?f=128%3D32t)
![t=4\ sec](https://tex.z-dn.net/?f=t%3D4%5C%20sec)
Hence, The maximum height attained by the object and the number of seconds are 128 ft and 4 sec.
It can be observed without changing the identity of the object.
Answer:
Kinetic Energy.
Explanation:
The movement of a roller coaster is accomplished by the conversion of potential energy to kinetic energy. The roller coaster cars gain potential energy as they are pulled to the top of the first hill. As the cars descend the potential energy is converted to kinetic energy.