To determine the height of the object given the time, we simply use the given relation between height and time in the problem statement. It is given as:
h = -16t^2 + 127t
We substitute 55 seconds to t and obtain,
h = -16(55)^2 + 127(55)
h = - 41415
Answer:
115, 80, 15m
Explanation
t1 = 14s
t2 = 18s
change in time = 4s (18-14)
r(final) = r(initial) + (average velocity) x (change in time)
multiply the average velocity with the change in time
= (4, 0, -3) x 4 = 16, 0, -12
now we'll add this value to the initial position of the car
(99, 80, 27)m + (16, 0, -12)m = (115, 80, 15)m
Answer:
Before giving an injection, a nurse dabs some alcohol onto the patient`s arm. This makes the patient`s skin feels cold. Explain Why ?
<em> Evaporative cooling makes this to be possible</em>
Explanation:
The concept
For a liquid to evaporate, there must be a breakdown of the bond between the molecules of the liquid. These bonds are broken when the molecules gain heat energy. So basically evaporation occurs when the molecules of the substance gain energy in form of heat.
Our Scenario
Just like the way our body excretes sweat on a sunny day, alcohol takes energy from the skin to evaporate. The bond holding the molecules of alcohol breaks faster due to its low boiling point and this account why it evaporates faster. The sudden evaporation of alcohol when dabbed on the skin results in quick utilization of heat energy making the skin feel cold for some time.
The utilization of heat energy from the skin results in evaporation cooling which makes the skin feel colder.
That is called fully constructive interference.
