Kinetic energy of hail stone

[dobbygenius]

Homework Statement

by reference to your answer in part (a), suggest whether hailstones are likely to melt on hitting the Earth's surface

Relevant Equations

mL=1/2mv^2

I'm pretty sure the hailstones are likely to melt/disperse because 824 m/s is a high velocity but can someone help me elaborate why it would melt?

 

[PeroK]

Homework Statement:: by reference to your answer in part (a), suggest whether hailstones are likely to melt on hitting the Earth's surface
Relevant Equations:: mL=1/2mv^2


I'm pretty sure the hailstones are likely to melt/disperse because 824 m/s is a high velocity but can someone help me elaborate why it would melt?

Do you mean to say the hailstones would melt? Or wouldn't melt?

 

[PeroK]

PS I'm not sure why all the KE would transform to heat in the hailstone. Why wouldn't about half the energy go to heat in the ground at the point of impact?

 

[dobbygenius]

Do you mean to say the hailstones would melt? Or wouldn't melt?

yes, the hailstones would melt...but I don't know how to elaborate on that

 

[dobbygenius]

PS I'm not sure why all the KE would transform to heat in the hailstone. Why wouldn't about half the energy go to heat in the ground at the point of impact?

You're right I just followed what the question said

 

[PeroK]

yes, the hailstones would melt...but I don't know how to elaborate on that

With what speed do hailstones hit the Earth?

 

[dobbygenius]

With what speed do hailstones hit the Earth?

the first question asked to find the minimum speed for it to melt when it hits the surface and I found it to be 824 m/s but other than that both the first and second question didn't give any more data

 

[PeroK]

the first question asked to find the minimum speed for it to melt when it hits the surface and I found it to be 824 m/s but other than that both the first and second question didn't give any more data

Do you think hailstones hit the ground at $824 \ m/s$ or more? Have you ever seen hailstones?

 

[haruspex]

I'm pretty sure the hailstones are likely to melt/disperse because 824 m/s is a high velocity but can someone help me elaborate why it would melt?

Your reasoning is backwards. If it requires a very high velocity to melt the hailstones then that makes it relatively unlikely that hailstones would melt in practice.
So the question is, is such a high impact speed likely?

PS I'm not sure why all the KE would transform to heat in the hailstone. Why wouldn't about half the energy go to heat in the ground at the point of impact?

Because most of the inelastic deformation would be in the ice.

 

[PeroK]

Because most of the inelastic deformation would be in the ice.

That's a subtle assumption. It depends what the hailstones hit. Large hailstones may damage a car roof, for example, causing inelastic deformation of the metal.

 

[dobbygenius]

Do you think hailstones hit the ground at $824 \ m/s$ or more? Have you ever seen hailstones?

No, I just looked it up, should've done it earlier

 

[dobbygenius]

Your reasoning is backwards. If it requires a very high velocity to melt the hailstones then that makes it relatively unlikely that hailstones would melt in practice.
So the question is, is such a high impact speed likely?

Because most of the inelastic deformation would be in the ice.

Right...thankyou!

 

[berkeman]

That would be a very noisy hailstorm! Lots and lots of little sonic booms