�?�?t ε l ρ l v l + �?�?ε l ρ l v l v l = ε l �?�?τ l + ε l ρ l g �?ε l �?p �?β v l �?v s Take note: Drillopedia.com is really a submission-dependent expertise-sharing web page. Contributors post details based on their own knowledge and expertise. Customers should really use their discretion when using the data