Week 3 Homework Assignment

 

  1. (P.95 Prob.4) Figure 3.30 show the vertical velocity component of a elevator versus time. If the elevator starts to move at t = 0s, when is the elevator at its highest location above the starting point?
  2. (P.96 Prob. 8) Figure 3.32 shows a graph of x(t) in meters for an object traveling in a straight line. What is v at t = 2.0s?
  3. (P.96 Prob.12) If a car traveling at 28m/s is brought to a full stop in 4.0s after the brakes are applied, find the average acceleration during braking.
  4. (P.97. Prob.24) A model sailboat is slowly sailing west across a pond. A gust of wind gives the sailboat a constant acceleration of magnitude 0.30m/s2 during the 2.0s interval has magnitude 0.375N, what is the sailboat's mass?
  5. (P.97 Prob.32) A train is traveling south at 24.0m/s when the brakes are applied. It slows down at a constant rate to a speed of 6.00m/s in a time of 9.00s. (a) What is the acceleration of the train during the 9.00s interval? (b) How far does the train travel during the 9.00s?
  6. (P.98 Prob.40) IN a television tube, electrons are accelerated from rest by a constant electric force of magnitude 6.4 x 10-17N during the first 2.0cm of tube's length; then they move at essentially constant velocity another 45cm before hitting the screen. (a) Find the speed of the electrons when they hit the screen. (b) How long does it take them to travel the length of the tube?
  7. (P.98 Prob.46) A 5.5kg lead ball is dropped from the leaning tower of Pisa. The tower is 55m high. (a) How far does the ball fall in the first 3.0s of flight? (b) What is the speed of the ball after it haas traveled 2.5m downward? (c) What is the speed of the ball 3.0s after it is released?
  8. (P.98 Prob.56) Luke stand s on a scale in an elevator that has a constant acceleration upward. The scale reads 0.960kN. When Luke picks up a box of mass 20.0kg, the scale reads 1.200kN. (The acceleration remains the same.) Let g = 9.8m/s2. (a) Find the acceleration of the elevator. (b) Find Luke's weight.