Two blocks \( A \) and \( B \) shown in (Figure 1) have a weight of 9 lb and 6 lb , respectively. They are resting on the incline for which the coefficients of static friction are \( \mu_{A}=0.13 \) and \( \mu_{B}=0.27 \). Determine the angle \( \theta \) which will cause motion of one of the blocks. What is the friction force under each of the blocks when this occurs? The spring has a stiffness of \( k=2 \mathrm{lb} / \mathrm{ft} \) and is originally unstretched. Figure Determine is the friction force under the block \( A \) at this angle. Express your answer to three significant figures and include the appropriate units. Request Answer Incorrect; Try Again; 3 attempts remaining Part C Determine is the friction force under the block \( B \) at this angle. Express your answer to three significant figures and include the appropriate units.