Answer:
16.935 N
Explanation:
In order to make the box start moving, the level force applied on the box (F) must be greater than the force of static friction that keeps the box at rest, which is equal to
where
is the coefficient of static friction
(mg) = 30 N is the weight of the box
Therefore, the condition for F must be:
So, the applied force must be greater than this value.
Answer:
-120000 W
Explanation:
Power = change in energy / time
P = ΔE / t
P = (½ mv₂² − ½ mv₁²) / t
P = m (v₂² − v₁²) / (2t)
Given m = 1.5 t = 1500 kg, v₂ = 10 m/s, v₁ = 30 m/s, and t = 5 s:
P = (1500 kg) ((10 m/s)² − (30 m/s)²) / (2 × 5 s)
P = -120000 W
<span>The loudness of the sound increases gradually as the air is slowly introduced in to the jar. This is because sound needs a physical medium and in a vacuum there is none. The air provides that medium and as it is introduced, the transfer of sound energy increases</span>
<span><u>Answer</u>
c). random internal motion of atoms and molecules.
<u>Explanation </u>
Diffusion is the movement of particles from a region of high concentration to region of low concentration. The rate of diffusion can be increased by increasing amount of temperature but this is not its primary cause. Diffusion is primarily caused by movement of molecules or atoms in a substances. Form the choices given, the correct answer is c. random internal motion of atoms and molecules.
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