As our story begins, the sled ... whose mass is 8 kg ... is sliding along the ice at a speed of 4 m/s.
The sled's kinetic energy is (1/2 m v²) = (4 kg · 16 m²/s²) = 64 J .
After what seems like only the blink of an eye, the sled is no longer sliding. It is stationary. Motionless. At Rest. Just sitting there !
Its speed has been reduced to zero and ... because kinetic energy is the energy of motion ... the sled's kinetic energy is now also zero. Sixty-four Joules of energy have disappeared !
How can this be ? ! ? We know that energy is conserved. It can never just appear out of nothing, and it can never just disappear into nothing. If energy suddenly appears, it had to come from somewhere, and if energy suddenly disappears, it had to go somewhere. So where did our 64 Joules of kinetic energy go ?
It went into the ice, THAT's where ! We can say that the sled did 64J of work, and melted a thin slick layer of water on the surface of the ice. OR we can say that friction did NEGATIVE 64J of work on the sled, to cancel the 64J that it had originally, sap its kinetic energy, and bring it to rest.
I think <em>choice-B</em> was supposed to say "<em>B. -64J</em>", but somebody typed it sloppily and neglected to proofread it before posting.
I think the correct answer from the choices listed above is option B. The question that the group of students came up with would be an extremely difficult question to answer scientifically because how people see or experience color is subjective and people might see it differently.
Answer:
Hot (A)
Explanation:
because there are electrons going through there, the friction between the metallic nuclei and electrons creates vibrations known as heat.
if you touch it the electrons will run through your body and caus damadge.
Answer:
To determine the minimum blade length, add 1" to the workpiece thickness. One type of material, and some materials can be cut by more than one type of blade. No matter the material, there's likely a jigsaw blade designed specifically for. Armed with the right blade, follow these pointers to make your work go (and cut) .
Explanation:
Explanation:
Mass : -
1. It is the amount of mass present in an object.
2. SI unit : Kilograms ( kg )
3. Relation between Mass and Weight is W = mg.
Weight : -
1. It is the force with which it is attracted towards the centre of the earth.
2. SI unit : Newton ( N )
3. Relation between Mass and Weight is W = mg.
