Answer:
Estimation: year 1110.
Explanation:
We need to know how much time it takes to move 100 arcseconds if it moves at 0.11 arcsecond per year. Similarly to any velocity equation , where in our case the distances are angular, we will obtain the time by doing:
Which, considering from 2019, the explosion ought to have been observed around 1110 (in reality it was observed by Chinese astronomers in 1054).
Answer:
V= 33.98 m/s
Explanation:
Given that
Horizontal speed ,u= 17 m/s
Time taken by rockets to strike the water ,t= 3 s
We know that acceleration due to gravity ,g= 9.81 m/s²
There is no any acceleration in the horizontal direction that is why the horizontal veloity will remain constant.
In the vertical direction
vy = uy+ g t
Initial velocity in vertical direction is 0 m/s.
vy= 0+ 9.81 x 3
vy = 29.43 m/s
The resultant velocity
V= 33.98 m/s
Answer:
the engine cool to 40 at 14.07 minutes
Explanation:
Given information
T(5) = 70
= 100
C = 15
Newton's law of cooling :
T(t) = C + ( - C)
where
T(t) = temperature at any given time
C = surrounding temperature
= initial temperature of heated object
k = cooling constant
to find the the time when the engine will be cooled down to 40, we first need to find the cooling constant, k
when t = 5, T(5) = 70
so,
T(t) = C + ( - C)
T(5) = 15 + (100 - 15)
70 = 15 + (85)
= (70 - 15) / 85
-5k = ln (55/85)
k = - ln (55/85) / 5
k = 0.087
thus, we have the eqaution
T(t) = 15 + (85)
now we can determine the time when T(t) = 40
40 = 15 + (85)
= (40-15)/85
-0.0087t = ln (25/85)
t = - ln (25/85)/0.087
t = 14.07 minutes