Which explains why conduction is unlikely when ice is placed on a freezer shelf? There is no direct contact. The ice is too cold
2 answers:
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Answer:
<h3>The answer is 3.81 kg</h3>Explanation:
The mass of the dog can be found by using the formula
f is the force
a is the acceleration
From the question we have
We have the final answer as
<h3>3.81 kg</h3>Hope this helps you
(a) the initial kinetic energy of the projectile is equal to:
The projectile is fired straight up, so at the top of its trajectory, its velocity is zero; this means that it has no kinetic energy left, so for the law of conservation of energy, all its energy has converted into potential energy, which is equal to
b) If the projectile is fired with an angle of
, its velocity has 2 components, one in the x-direction and one in the y-direction:
This means that at the top of its trajectory, only the vertical velocity will be zero (because the horizontal velocity is constant, since the motion on the x-axis is a uniform motion). Therefore, at the top of the trajectory, the projectile will have some kinetic energy left:
For the conservation of energy, the initial energy mechanical energy must be equal to the mechanical energy at the highest point:
the initial kinetic energy is the same as point a), so we can re-arrange this equation to find the new potential energy at the top of the trajectory:
The projectile is fired straight up, so at the top of its trajectory, its velocity is zero; this means that it has no kinetic energy left, so for the law of conservation of energy, all its energy has converted into potential energy, which is equal to
b) If the projectile is fired with an angle of
This means that at the top of its trajectory, only the vertical velocity will be zero (because the horizontal velocity is constant, since the motion on the x-axis is a uniform motion). Therefore, at the top of the trajectory, the projectile will have some kinetic energy left:
For the conservation of energy, the initial energy mechanical energy must be equal to the mechanical energy at the highest point:
the initial kinetic energy is the same as point a), so we can re-arrange this equation to find the new potential energy at the top of the trajectory:
Answer:
the answers, the correct one is A v= 22.5 m/s
Explanation:
We can solve this problem using the concepts of conservation of mechanical energy
Starting point. Lowest point of the trajectory
Em₀ = K = ½ m v₀²
Final point. When it is at a height of y = 20 m
= K + U = ½ m v² + mg y
how energy is conserved
Emo = Emf
½ m v₀² = ½ m v² + m g y
v² = v₀² + 2 g y
let's calculate
v²2 = 30 2 + 2 9.8 20
v² = 508
v²= ra 508
v² = 22.54 m / s
When checking the answers, the correct one is A