7. [-/1.33 Points] DETAILS SERPSE7 4.P.027. MY NOTES ASK YOUR TEACHER Young David who slew Goliath experimented with slings before tackling the giant. He found that he could revolve a sling of length 0.500 m at the rate of 9.00 rev/s. If he increased the length to 0.800 m, he could revolve the sling only 7.00 times per second. (a) What is the speed of the stone for each rate of rotation? m/s at 9.00 rev/s m/s at 7.00 rev/s (b) What is the centripetal acceleration of the stone at 9.00 rev/s? m/s (c) What is the centripetal acceleration at 7.00 rev/s? m/'s 8. [-/1.33 Points] DETAILS SERPSE7 4.P.030. MY NOTES ASK YOUR TEACHER A bell swings in a vertical circle at the end of a rope 1.50 m long. When the ball is 36.70 past the lowest point on its way up, its total acceleration is (-22.5 i + 20.2 j) m/s?. (a) At that instant, sketch a vector diagram showing the components of its acceleration. (Do this on paper. Your instructor may ask you to turn in the sketch.) (b) Determine the magnitude of its radial acceleration. 7m/s2 + (c) Determine the speed and velocity of the ball. speed m/s velocity m/s (magnitude) (above the horizontal)Barry Bonds hits a home run so that the baseball just clears the top row of bleachers, 21 m high, located 130 m from the home plate. The ball is hit at an angle of 35 to the horizontal, and air resistance is negligible. Assume that the ball is hit at a height of 1.00 m above the ground. Find the following values. (a) the initial speed of the ball m/s (b) the time at which the ball reaches the cheap seats (c) the velocity of the ball when it passes over the top row jim's + i m/s the speed of the ball when it passes over the top row m/'s 10. [-/1.33 Points] DETAILS SERPSE7 4.P.047. MY NOTES ASK YOUR TEACHER A pendulum of length 1.20 m swings in a vertical plane (see figure). When the pendulum is in the two horizontal positions @ = 900 and @ = 2700, its speed is 5.70 m/s. + (a) Find the magnitude of the radial acceleration and tangential acceleration for these positions. radial acceleration Im/s2 tangential acceleration m/s (b) Draw a vector diagram to determine the direction of the total acceleration for these two positions. (Do this on paper, Your instructor may ask you to turn in this work.) (c) Calculate the magnitude and direction of the total acceleration. m/s? at 9-Select- v the horizontal