Question

Think and answer
1. A dog and a horse are running at the same speed. Who has more kinetic energy and why?
2. A body is thrown vertically upwards. What happens to its kinetic energy at its highest point?
3. The sum total of energy in this universe is constant. Justify this statement​

Answer 1

Explanation:

1.) Given that,

a dog and a horse is running at a same speed

a horse always has a greater mass than dog

and

Kinetic energy = ½ mv²

here,

K.E. is directly proportional to mass

so,

if mass will greater then kinetic energy will also greater

here,

since velocity of both is same but

mass of horse is greater than the dog

so,

kinetic energy of horse is greater than of dog

2.) When a body is thrown vertically upwards its velocity goes on decreasing so it kinetic energy also decreasing and at its maximum height velocity becomes zero

so,

Its kinetic energy will also zero

3.) The sum of total energy in the universe is constant because energy can neither be created and nor be destroyed.

It is only converted to the another form of energy hence it is constant

Answer 2

1. A dog and a horse are running at the same speed. Who has more kinetic energy and why?

AnswEr :

⋆ Kinetic Energy = 1/2 × mv²

where m = Mass and, v = Speed

Mass of Horse > Mass of Dog

Let's Assume that Speed is Constant here.

So, the Horse Must Have have More Kinetic Energy because Horse has more Mass than Dog and Speed is Constant.

2. A body is thrown vertically upwards. What happens to its kinetic energy at its highest point?

AnswEr :

⋆ When a body is thrown upwards, its kinetic energy gradually changes into potential energy.

⋆ At the highest point where its velocity becomes zero, whole of the kinetic energy gets converted into potential energy.

3. The sum total of energy in this universe is constant. Justify this statement.

AnswEr :

⋆ We Know that Energy neither Created nor Destroyed, it can only change into other form. According to the 'Law of Conservation of Energy's the sum of all types of energy is constant.

჻ The sum total of energy in this universe is constant.