Answer:
(a). The initial velocity is 28.58m/s
(b). The speed when touching the ground is 33.3m/s.
Explanation:
The equations governing the position of the projectile are


where
is the initial velocity.
(a).
When the projectile hits the 50m mark,
; therefore,

solving for
we get:

Thus, the projectile must hit the 50m mark in 1.75s, and this condition demands from equation (1) that

which gives

(b).
The horizontal velocity remains unchanged just before the projectile touches the ground because gravity acts only along the vertical direction; therefore,

the vertical component of the velocity is

which gives a speed
of


The chemical formula of the compound of strontium and chlorine would be SrCl2. It is a salt of the strontium ion and chloride ion and a white crystalline compound. When burned, it produces a bright red hue. That is why it found some application in fireworks.
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Since there is no temperature change which drives heat flow, thus no heat will be released by the water.
<h3>
Heat released by the water when it freezes</h3>
The heat released by the water when it freezes is calculated as follows;
Q = mcΔФ
where;
- m is mass of water
- c is specific heat capacity of water
- ΔФ is change in temperature = Фf - Фi
when water freezes, the temperature, Фf = 0 °C
Q = 82 x 4200 x (0 - 0)
Q = 0
Since there is no temperature change which drives heat flow, thus no heat will be released by the water.
Learn more about heat flow here: brainly.com/question/14437874
Answer:
a = 252 m / s²
Explanation:
The initial speed Vο = 0
The speed of baseball with witch it is thrown Vf = 42 m/s
Displacement covered = 3.5 m
Hence acceleration will be constant at this moment, so as per the equation of constant acceleration : ( Vf² - Vο² ) / 2d = a
a = 252 m / s²
The particles of a liquid are packed together rather than a gas where the particles are everywhere and not together.