10. In the following figure, the horizontal surface on which this block slides is frictionless. If the two forces acting on it each have magnitude F = 30.0 N and M = 10.0 kg, what is the magnitude of the resulting acceleration of the block? 30 M 11. A student with mass 45 kg jumps off a high diving board. Using 6.0 x 1024 kg for the mass of the earth, what is the acceleration of the earth toward her as she accelerates toward the earth with an acceleration of 9.81 m/s2? (Hint: Use Newton's Third Law to determine the net gravitational force the student exerts on the earth.) 12. A bird has a mass of 26 g and perches in the middle of a stretched telephone line. (a) Show that the tension in the line can be calculated using the equation F = 2sing . Determine the tension when (b) 0 =5 and (c) 0 = 0.5. Assume that each half of the line is straight. 13. When starting a foot race, a 70.0-kg sprinter exerts an average force of 650 N backward on the ground for 0.800 s. (a) What is his final speed? (b) How far does he travel? 14. In a particle accelerator, a proton has mass 1.67 x 10 2 kg and an initial speed of 2.00 x 105 m/s. It moves in a straight line, and its speed increases to 9.00 x 105 m/s in a distance of 10.0 cm. Assume that the acceleration is constant. Find the magnitude of the force exerted on the proton