AskQ logo

STUCK ON HOMEWORK?

ASK FOR HELP FROM OUR KIASUPARENTS.COM COMMUNITY!

Question

post-18092

Can someone please explain these to me? Is the correct answer C?

Answer

Whether it’s potential, heat and in this case, kinetic energy, mass is a factor of the energy.

For the same speed, the more mass, the more energy it has.

Same for gravitational potential energy. For the same height, the more mass, the more energy.

Same for heat energy. For the same temperature difference of the same material, the more mass the more heat energy transferred. 

Even chemical energy like your lithium battery. the more mAH the battery has, the heavier it is.

As the kid gets into higher secondary level to study the formulas of all the different types of energy, there is always a “m” in the formula.

So I think the kid right now has to know is mass is one of the  factor of energy. Which I think is the purpose of this question.

0 Replies 1 Like

I think my photo of the textbook is too big a file. Not sure if Sec 1 has been taught KE=1/2 mv2.

(m is mass, v is velocity or speed)

Taken from textbook:

“from the equation,

  • the same mass moving at different speeds, the faster object has greater KE;
  • different masses moving at the same speed, the object of greater mass has greater KE.

To apply to general observations, it is much more detrimental to be hit by a lorry than a bicycle even though both are travelling at the same speed, due to higher KE from greater mass. (Inertia does a part too but I think out of scope. )

Kids will remember better by Internalising concepts to general observations. 

0 Replies 0 Likes