Answer:
<em>Correct choice: b 4H</em>
Explanation:
<u>Conservation of the mechanical energy</u>
The mechanical energy is the sum of the gravitational potential energy GPE (U) and the kinetic energy KE (K):
E = U + K
The GPE is calculated as:
U = mgh
And the kinetic energy is:
Where:
m = mass of the object
g = gravitational acceleration
h = height of the object
v = speed at which the object moves
When the snowball is dropped from a height H, it has zero speed and therefore zero kinetic energy, thus the mechanical energy is:
When the snowball reaches the ground, the height is zero and the GPE is also zero, thus the mechanical energy is:
Since the energy is conserved, U1=U2
![\displaystyle mgH=\frac{1}{2}mv^2 \qquad\qquad [1]](https://tex.z-dn.net/?f=%5Cdisplaystyle%20mgH%3D%5Cfrac%7B1%7D%7B2%7Dmv%5E2%20%20%20%20%5Cqquad%5Cqquad%20%5B1%5D)
For the speed to be double, we need to drop the snowball from a height H', and:
Operating:
![\displaystyle mgH'=4\frac{1}{2}m(v)^2 \qquad\qquad [2]](https://tex.z-dn.net/?f=%5Cdisplaystyle%20mgH%27%3D4%5Cfrac%7B1%7D%7B2%7Dm%28v%29%5E2%20%5Cqquad%5Cqquad%20%5B2%5D)
Dividing [2] by [1]
Simplifying:
Thus:
H' = 4H
Correct choice: b 4H
I believe gamma decay but i may be wrong
Answer:
The terminal velocity is 
Explanation:
From the question we are told that
The mass of the squirrel is 
The surface area is 
The height of fall is h =4.8 m
The length of the prism is 
The width of the prism is 
The terminal velocity is mathematically represented as
Where 
is the density of a rectangular prism with a constant values of 
is the drag coefficient for a horizontal skydiver with a value = 1
A is the area of the prism the squirrel is assumed to be which is mathematically represented as
substituting values
Answer:
D
Explanation:
Let’s calculate the kinetic energy for all of the choices.
a. (1/2)(100)(100)^2 = 50(10000)=500,000
b. (1/2)(100)(1)^2 = 50
c. (1/2)(10)(100)^2 = 5(10000) = 50,000
d. (1/2)(1)(1)^2 = 0.5
We can see that (d) has the least kinetic energy.
Answer:
Friction always acts in the direction opposing motion. This means if friction is present, it counteracts and cancels some of the force causing the motion (if the object is being accelerated).
Explanation:
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other.
