Out of the choices provided I would choose B, this is because A is wrong due to simple machines making our work easier and require less energy, C is wrong due to the work actually being done faster due to simple machines. Now D and B felt like they were both correct but D just doesn't make much since when you apply it to the topic of Simple machines so I found B.
You’re using more force to kick the brick than to push it gently.
The first object also has half the inertia.
Answer: Option A
<u>Explanation:</u>
Inertia is the tendency of an object to remain in its state. It resists the change in the state of object due to any external forces. So the inertia is the property of an object to resists the change in its state due to any kind of external force. Thus as the mass decreases, the central mass of inertia of the object will also decrease as both are directly proportional to each other.
Answer:
option C
Explanation:
the correct answer is option C.
All the activity such as Radioactive isotopes, differentiation of Earth’s iron core, gravity-driven compression,and meteoric bombardment will make the earth hotter than what it is at present.
Radioactive isotope whose nuclei are unstable dissipate excess energy.
Differentiation of iron core means formation of into layer which includes iron.
meteorite bombardment will affect the atmosphere of the earth which protect harmful radiation.
All these activity will make earth hotter
Answer:
1.58 W
Explanation:
Since the sound spreads uniformly in all directions, it must be in a form of a circle with radius of 12 m. So the area of the circle is
From the intensity of the sound we can calculate the power at 12 m
