If you wanted to find the area of the hot filament in a light bulb, you would have to know the temperature (determinable from th
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Answer:
The final velocity of the bullet is 9 m/s.
Explanation:
We have,
Mass of a bullet is, m = 0.05 kg
Mass of wooden block is, M = 5 kg
Initial speed of bullet, v = 909 m/s
The bullet embeds itself in the block which flies off its stand. Let V is the final velocity of the bullet. The this case, momentum of the system remains conserved. So,
So, the final velocity of the bullet is 9 m/s.
Answer:
D) The objects velocity is zero when its acceleration is a maximum
Explanation:
In a simple harmonic motion, the total energy is constant (if we neglect air resistance and friction), and it is equal to the sum of the elastic potential energy U and the kinetic energy K:
(1)
where
m is the mass
v is the velocity
k is the spring constant
x is the displacement
As a consequence, since E must remain constant, when K increases U decreases, and vice-versa.
Also, in a simple harmonic motion the acceleration of the system is proportional to the negative of the displacement:
(2)
So, combining (1) with (2), we have the following situations:
- When the displacement is zero (x=0), the acceleration is also zero (a=0), and so the velocity is maximum, because the kinetic energy is maximum
- When the displacement is maximum (x=max), the acceleration is also maximum, while the velocity is zero because the kinetic energy is zero
So, the correct statement is
D) The objects velocity is zero when its acceleration is a maximum