Answer:
The expression for the initial speed of the fired projectile is:
And the initial speed ratio for the 9.0mm/44-caliber bullet is 1.773.
Explanation:
For the expression for the initial speed of the projectile, we can separate the problem in two phases. The first one is the moment before and after the impact. The second phase is the rising of the ballistic pendulum.
First Phase: Impact
In the process of the impact, the net external forces acting in the system bullet-pendulum are null. Therefore the linear momentum remains even (Conservation of linear momentum). This means:
(1)
Second Phase: pendular movement
After the impact, there isn't any non-conservative force doing work in al the process. Therefore the mechanical energy remains constant (Conservation Of Mechanical Energy). Therefore:
(2)
The height of the pendulum respect L and θ is:
(3)
Using equations (1),(2) and (3):
(4)
The initial speed ratio for the 9.0mm/44-caliber bullet is obtained using equation (4):
Answer:
At 100°C, the pH of pure water is 6.14. That is the neutral point on the pH scale at this higher temperature. A solution with a pH of 7 at this temperature is slightly alkaline because its pH is a bit higher than the neutral value of 6.14.
Explanation:
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Answer:
<em>The average speed is 22.2 km/h</em>
Explanation:
<u>Average Speed</u>
Given an object travels a total distance d and took a total time t, then the average speed is:
The mailman first drives d1=7 km at v1=15 km/h. The time taken to drive is:
Then he drives d2=7 km at v2=43 km/h taking a time of:
The total time is
t=0.467 h + 0.163 h = 0.63 h
The total distance is
d = 7 km + 7 km = 14 km
The average speed is:
The average speed is 22.2 km/h