Answer:
1.when it is closest to the sun
2.when it is midway between its farthest
Step-by-step explanation:
According to the law of Kepler's
T ² ∝ r³
T=Time period
r=semi major axis
We also know that time period T given as
![T=(2\pi r)/(v)](https://img.qammunity.org/2020/formulas/physics/high-school/lxcienkar4a33urkje2xw23bab38pufsfn.png)
v=Speed
![v=(2\pi r)/(T)](https://img.qammunity.org/2020/formulas/physics/college/a61mxrkx5730qj4acdsmvtots6ypkv3h1q.png)
![v\alpha (r)/(T)](https://img.qammunity.org/2020/formulas/physics/college/710tv645i5g1q79dh43ko2hgfpe8npkqm9.png)
![v\alpha (r)/(T)](https://img.qammunity.org/2020/formulas/physics/college/710tv645i5g1q79dh43ko2hgfpe8npkqm9.png)
![v^2\alpha (r^2)/(T^2)](https://img.qammunity.org/2020/formulas/physics/college/ctidrh1jdtxm2u7ne6ixkbdnycfkv2uinh.png)
![v^2\alpha (r^2)/(r^3)](https://img.qammunity.org/2020/formulas/physics/college/8ghaze01fbg71s6u4972qo0e1wo0xpwzw0.png)
![v^2\alpha (1)/(r)](https://img.qammunity.org/2020/formulas/physics/college/vskicq91q41zh5171rntu79xypxtx3e8vq.png)
![v\alpha (1)/(√(r))](https://img.qammunity.org/2020/formulas/physics/college/hjtegkbwut0y13db8hq2w8ajly8fwxnjl8.png)
So we can say that ,when r is more then the speed will be minimum and when r is low then speed will be maximum.