Here we can use momentum conservation as in this type of collision there is no external force on it

now here we can say




now here we can say


now by coefficient of restitution
for elastic collision we know that e = 1


now by solving the two equation


also we know that

so final speed of the nail is 6.875 m/s
Because of the earths curve and temperature. The temperature in an area depends on the amount of the Sun's energy reaching the surface in that area. The equator tilts closer to the sun than the poles do. I hope this helps!
The answer to that question is c. tamod
Either A or D. If I were answering I'd go with my git answer and say A
There’s not enough info here i’m sorry