Which of the following statements is true? The melting and freezing points of a substance are the same. The melting and boiling
2 answers:
Answer:
The melting and freezing points of a substance are the same
Explanation:
Melting occurs when the state of a substance changes from solid to liquid, while freezing occurs when the state of a substance changes from liquid to solid. Therefore, melting and freezing are one the inverse process of the other: it means that they occur at the same temperature.
For instance, the melting point of ice (at standard pressure) is , and the freezing point of water is at the same temperature,
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Answer:
0.0613°C
Explanation:
the given parameters are m=15gm=15×10⁻³ V₁=865m/s V₂=534m/s
the bullet moves with different kinetic energies before and after the penetration, therefore
Kinetic energy before - kinetic energy after = 1/2 × m × ( V₁² - V₂²)
= × 15×10⁻³ × (865² - 534²)
= 3.47 × 10⁻³J
this loss in energy is transferred to the water, therefore
change in temperature =
where c = heat capacity of water = 4.19 x 10^3
m = mass of water = 13.5 kg
= {3.47 × 10⁻³} / {13.5 x 4.19 x 10^3 }
=0.0613°C
(a) The turtle's initial velocity is 4 m/s, initial position of the turtle is 5 cm, and initial acceleration is -1.25 m/s².
(b) The time when the velocity of the turtle is zero is 3.2 s.
(c) The time taken for the turtle to return to its starting point is 6.4 s.
(d) The time taken for the turtle to travel 30 cm is 0.08 s.
<h3>Initial velocity of the turtle</h3>The initial velocity of the turtle is calculated as follows;
The initial acceleration of the turtle is calculated as follows;
x(t) = 5 + 4t - 0.625t²
x(0) = 5 cm
<h3>Time when the velocity becomes zero</h3>v(t) = 4 - 1.25t
0 = 4 - 1.25t
1.25t = 4
t = 4/1.25
t = 3.2 s
<h3>Time taken to return to starting point</h3>The total distance traveled is calculated as follows
v² = u² + 2ad
0 = (4)² + 2(-1.25)d
0 = 16 - 2.5d
2.5d = 16
d = 16/2.5
d = 6.4 m
Time to travel the given distance;
d = ut + ¹/₂at²
6.4 = (4)t + ¹/₂(-1.25)t²
6.4 = 4t - 0.625t²
0.625t² - 4t + 6.4 = 0
solve the quadratic equation using formula method;
t = 3.2 s
The time travel the distance two times, = 2 x 3.2 s = 6.4 s
<h3>Time taken for the turtle to travel 30 cm</h3>d = ut + ¹/₂at²
0.3 = (4)t + ¹/₂(-1.25)t²
0.3 = 4t - 0.625t²
0.625t² - 4t + 0.3 = 0
solve the quadratic equation using formula method;
t = 0.08 s
Learn more about velocity here: brainly.com/question/6504879