Physical Science Take 10 Week # 6

Day # 1 Question 1 A. 0 N B. 70 N C. 670 N D. 1270 N The forces acting on a skateboarder moving at a constant velocity along a sidewalk are shown in the figure. Which of the following is the net force on the skateboarder? A. 0 N B. 70 N C. 670 N D. 1270 N

Day # 1 Question 2 An upward force of 150 N is applied to an object weighing 70 N. Which of the following describes this situation?

Day #1 Answers Which of the following is the net force on the skateboarder ? A. 0 N 2. An upward force of 150 N is applied to a box weighing 70 N. Which of the following is the free-body force diagram for this situation?

Day #2 Question 1 Which of the following will definitely cause a change in the velocity of a parked car? A. The car experiences an unbalanced force. B. All forces acting on the car increase by 1 N. C. All forces acting on the car decrease by D. The forces acting on the car are equal and balanced.

Day #2 Question 2 A crane lifts two 100 kg loads of building materials to the top of a building under construction. The first load is lifted in 10 s and the second load is lifted in 13 s. Which of the following statements best compares the work and power expended by the crane lifting the two loads? A. The crane does more work and expends more power for the first lift. B. The crane does the same work and expends the same power for each lift. C. The crane does the same work for each lift but expends more power for the first lift. D. The crane does more work in the second lift but expends the same power for each lift.

Day # 2 Answers 2. Which of the following statements best compares the work and power expended by the crane lifting the two loads? C. The crane does the same work for each lift but expends more power for the first lift.

Day # 3 Question 1 Four students of different weights timed themselves walking up a set of stairs. Their data are shown below. Which student used the most power while walking up the stairs? A. student W B. student X C. student Y D. student Z

Day # 3 Question 2 A. 667 W B. 133 W C. 66 W D. 7 W A man ran on a treadmill for 1,800 seconds. At the end of his run, the treadmill indicated his energy output as 240,000 J. What average power did he generate? A. 667 W B. 133 W C. 66 W D. 7 W

Day # 3 Answers 1. Which student used the most power while walking up the stairs? student W 2. A man ran on a treadmill for 1,800 seconds. At the end of his run, the treadmill indicated his energy output as 240,000 J. What average power did he generate? B. 133 W

Day #4 Question 1 The diagram shows a motor being used to lift a load with the use of a pulley. The motor is lifting the 6 kg box at a constant velocity. How much work is done on the box to lift it 2 m? (Trickier than you think) A. 3 J B. 12 J C. 60 J D. 120 J

Day # 4 Question 2 Two students are each carrying a box up to the third floor of a building. The total mass of each student and the box she is carrying is the same. Roberta makes the trip in 45 s while Mary takes 30 s. Which of the following statements best describes this task? A. Roberta does more total work than Mary. B. Mary does more total work than Roberta. C. Roberta has a greater power output than Mary. D. Mary has a greater power output than Roberta.

Day # 4 Answers 1. The motor is lifting the 6 kg box at a constant velocity. How much work is done on the box to lift it 2 m? (Assume no resistance from the pulley.) D. 120 J 2. Which of the following statements best describes this task? D. Mary has a greater power output than Roberta.

1. How many students are currently passing in 2nd block. A) 0. B) 4 1. How many students are currently passing in 2nd block? A) 0 B) 4 C) 6 D) 10 2. How many students have not taken their test (challenge)? A) 0 B) 2 C) 6 D) 10