The element is iridium and it has 77 electrons
Answer:
(a)
![x_1=17.68km\\y_1=-17.68km\\x_2=20km\\y_2=34.64km](https://tex.z-dn.net/?f=x_1%3D17.68km%5C%5Cy_1%3D-17.68km%5C%5Cx_2%3D20km%5C%5Cy_2%3D34.64km)
(b) ![r=41.32km](https://tex.z-dn.net/?f=r%3D41.32km)
![\alpha =24.23^o](https://tex.z-dn.net/?f=%5Calpha%20%3D24.23%5Eo)
Explanation:
Let us take the north direction to be the positive y-axis and the east to be positive x-axis.
First day:
25.0 km southeast, which implies
south of east. The y-component will be negative and the x-component will be positive.
![x_1=25cos45^o=17.68km](https://tex.z-dn.net/?f=x_1%3D25cos45%5Eo%3D17.68km)
![y_1=-25sin45^o=-17.68km](https://tex.z-dn.net/?f=y_1%3D-25sin45%5Eo%3D-17.68km)
Second day:
She starts off at the stopping point of last day. This time, both the y- and x-components are positive.
![x_2=40cos60^o=20km](https://tex.z-dn.net/?f=x_2%3D40cos60%5Eo%3D20km)
![y_2=40sin60^o=34.64km](https://tex.z-dn.net/?f=y_2%3D40sin60%5Eo%3D34.64km)
Therefore, total displacements:
![x=x_1+x_2=(17.68+20)km=37.68km](https://tex.z-dn.net/?f=x%3Dx_1%2Bx_2%3D%2817.68%2B20%29km%3D37.68km)
![y=y_1+y_2=(-17.68+34.64)km=16.96km](https://tex.z-dn.net/?f=y%3Dy_1%2By_2%3D%28-17.68%2B34.64%29km%3D16.96km)
Magnitude of displacements,
![r=\sqrt{x^2+y^2}=41.32km](https://tex.z-dn.net/?f=r%3D%5Csqrt%7Bx%5E2%2By%5E2%7D%3D41.32km)
Direction,
![\alpha =tan^{-1}(\frac{y}{x})=24.23^o](https://tex.z-dn.net/?f=%5Calpha%20%3Dtan%5E%7B-1%7D%28%5Cfrac%7By%7D%7Bx%7D%29%3D24.23%5Eo)
In the beginning, the melting stage they call it.