Answer:
Explanation:
Total weight
My weight+weight of belongings
660+1100=1760N.
a. Work done by the elevator to travel a total height of 15.2m
Using newton law of motion
ΣF = ma
There are only two forces acting upward, the weight and the reaction by the elevator
Also note it is moving at constant velocity then, a=0
N - W=0
Then, N=W
N=1760N
So, workdone is given as
Wordone, =force × distance
Work done=1760×15.2
W=26,752J
W=26.752KJ
b. Work done on me alone is still need to go through the same process but will remove the weight of the belonging
Therefore,
Weight now = 660N
And using the same equation of motion
ΣF = ma
Comstant velocity, a=0
N - W=0
N=W
N=660N
Then, workdone
W=F×d
W=660×15.2
W=10,032J
W=10.032KJ
Before a person walks through burning coal, the person will make sure their feet are very wet. When they start walking on the coal, this moisture will evaporate and form a protective gas layer underneath the person's feet. You can see examples of this if you happen to drip some water on a hot stove or any very hot surface. The water will very easily glide around on top of a newly formed layer of air underneath it -- like air hockey pucks on an air hockey table. Note that when someone walks through burning coal, typically this is also done very quickly to prevent a great deal of exposure to possible harm. By walking quickly, thinking positively, and letting the water cushion you from immediate danger over a short distance, such a task is possible. You may have also heard of physics teachers demonstrating how this principle works by sticking their hand first in a bucket of water and then quickly in a bucket of boiling molten lead. In the lead, their hand is protected briefly by a layer of gas from the evaporated water (the water vapor). I'm fairly sure that there is a name for this particular layer of gas, but I'm afraid the name is beyond me at the moment. In other words, water vapor has a low heat capacity and poor thermal conduction. Very often, the coals or wood embers that are used in fire walking also have a low heat capacity. Sweat produced on the bottom of people's feet also helps form a protective water vapor. All of this together makes it possible, if moving quickly enough, to walk across hot coals without getting burned. WARNING: Do not attempt to perform any of the actions described above. You can seriously injure yourself. Answered by: Ted Pavlic, Electrical Engineering Undergrad Student, Ohio St. (citing my source)
Answer:
3.71 m/s in the negative direction
Explanation:
From collisions in momentum, we can establish the formula required here which is;
m1•u1 + m2•v2 = m1•v1 + m2•v2
Now, we are given;
m1 = 1.5 kg
m2 = 14 kg
u1 = 11 m/s
v1 = -1 m/s (negative due to the negative direction it is approaching)
u2 = -5 m/s (negative due to the negative direction it is moving)
Thus;
(1.5 × 11) + (14 × -5) = (1.5 × -1) + (14 × v2)
This gives;
16.5 - 70 = -1.5 + 14v2
Rearranging, we have;
16.5 + 1.5 - 70 = 14v2
-52 = 14v2
v2 = - 52/14
v2 = 3.71 m/s in the negative direction
Answer:
Vx = 35 x cos(13deg)
Vy = 35 x sin(13deg) - gt
(g is acceleration due to gravity =~9.8 meter/second^2, t is time in second)
Explanation:
The tiger leaps up, then x and y component of its velocity are:
Vx = Vo x cos(alpha)
Vy = Vo x sin(alpha) - gt
(Vo is tiger's initial velocity, alpha is angle between its leaping direction and horizontal plane)
Hope this helps!
Nuclear energy is released during: fission. radioactive decay. man-induced splitting of atoms. Match the basic components of a nuclear reactor with their descriptions. 1. slows down neutrons -> moderator. 2. absorb emitted neutrons -> control rods.
