12. [0/6 Points] DETAILS PREVIOUS ANSWERS SERPSE10 4.5.OP.025.MI. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A train slows down as it rounds a sharp horizontal turn, going from 80.0 km/h to 44.0 km/h in the 12.0 s that it takes to round the bend. The radius of the curve is 160 m. Compute the acceleration at the moment the train speed reaches 44.0 km/h. Assume the train continues to slow down at this time at the same rate. magnitude X Your..response differs from the correct answer by more than 10%. Double check your calculations. m/s2 direction Ex . backward (behind the radial line pointing inward) Enter a number. Need Help? Read it Master It Submit Answer2. [6/9 Points] DETAILS PREVIOUS ANSWERS SERPSE10 4.1.P.001. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Suppose the position vector for a particle is given as a function of time by r(t) = x(t)i + y(t)i, with x(t) = at + b and y(t) = ct~ + d, where a = 1.30 m/s, b = 1.05 m, c = 0.124 m/s , and d = 1.04 m. (a) Calculate the average velocity during the time interval from t = 2.15 s to t = 3.95 s. V = m/s X (b) Determine the velocity at t = 2.15 s. V = 1.3i + 0.53j m/s Determine the speed at t = 2.15 s. 1.40 m/s Need Help? Read It Submit Answer6. [4/6 Points] DETAILS PREVIOUS ANSWERS SERPSE10 4.3.OP.010. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A ball is tossed from an upper-story window of a building. The ball is given an initial velocity of 9.30 m/s at an angle of 25.0 below the horizontal. It strikes the ground 6.00 s later. (a) How far horizontally from the base of the building does the ball strike the ground? 50.6 m (b) Find the height from which the ball was thrown. 200.0 m (c) How long does it take the ball to reach a point 10.0 m below the level of launching? S Need Help? Read It Watch It Submit AnswerChildren playing in a playground on the flat roof of a city school lose their ball to the parking lot below. One of the teachers kicks the ball back up to the children as shown in the figure below. The playground is 5.90 m above the parking lot, and the school building's vertical wall is h = 7.20 m high, forming a 1.30 m high railing around the playground. The ball is launched at an angle of 0 = 53.0 above the horizontal at a point d = 24.0 m from the base of the building wall. The ball takes 2.20 s to reach a point vertically above the wall. (Due to the nature of this problem, do not use rounded intermediate values in your calculations-including answers submitted in WebAssign.) (a) Find the speed (in m/s) at which the ball was launched. 18.13 m/s (b) Find the vertical distance (in m) by which the ball clears the wall. 0.933 m (c) Find the horizontal distance (in m) from the wall to the point on the roof where the ball lands. X You found the total horizontal distance the ball travels. Can you use this to find the horizontal distance it travels beyond the wall? m (d) What If? If the teacher always launches the ball with the speed found in part (a), what is the minimum angle (in degrees above the horizontal) at which he can launch the ball and still clear the playground railing? (Hint: You may need to use the trigonometric identity sec (0) = 1 + tan?(0).) 46.67 . above the horizontal (e) What would be the horizontal distance (in m) from the wall to the point on the roof where the ball lands in this case? Enter a number. you use should be identical to part (c), only now the initial angle is the value found in part (d). m