Chapter 4 Physics test

13. A cat leaps to try to catch a bird. If the cat's jump was at 60° off the ground and its initial velocity was 2.74 m/s, what is the highest point of its trajectory, neglecting air resistance? *

0.29 m

14. A hunter points a rifle horizontally and holds it 3.30 m above the ground. The bullet leaves the barrel at 325 m/s and experiences no significant air resistance. The acceleration due to gravity is 9.8 m/s² at this location. How long does it take for the bullet to strike the ground? *

0.821 s

3. If vectors A + B = C and their magnitudes A + B = 0, then vectors A and B are oriented *

antiparallel to each other (in opposite directions).

2. If vectors A + B = C and their magnitudes A + B = C, then vectors A and B are oriented *

parallel to each other (in the same direction).

6. For general projectile motion with no air resistance, the vertical component of a projectile's acceleration *

remains a non-zero constant.

10. The x and y components of a vector in the horizontal plane are 8 m and 6 m respectively. What is the magnitude of this vector? *

10 m

12. A girl throws a rock horizontally, with a velocity of 10 m/s, from a bridge. It falls 20 m to the water below. How far does the rock travel horizontally before striking the water, assuming negligible air resistance? *

20 m

15. A hunter points a rifle horizontally and holds it 3.30 m above the ground. The bullet leaves the barrel at 325 m/s and experiences no significant air resistance. The acceleration due to gravity is 9.8 m/s² at this location. How far horizontally does it travel? *

266.8 m

11. The x and y components of a vector in the horizontal plane are 8 m and 6 m respectively. What angle does this vector make with the + x-axis? *

36.9

9. Mary and Debra stand on a snow-covered roof. They both throw snowballs with the same initial speed, but in different directions. Mary throws her snowball downward, at 30° below the horizontal: Debra throws her snowball upward, at 30° above the horizontal. Which of the following statements is true about the snowballs as they just reach the ground? *

Both snowballs reach the ground with the same speed.

7. In an air-free chamber, a pebble is thrown horizontally, and at the same instant a second pebble is dropped from the same height. Compare the times of fall of the two pebbles. *

They hit at the same time.

8. A pilot drops a package from a plane flying horizontally at a constant speed. Neglecting air resistance, when the package hits the ground the horizontal location of the plane will *

be directly over the package.

1. Two vectors have magnitudes of 5.0 m and 7.0 m respectively. If these two vectors are added together, the magnitude of the sum *

could be as small as 2.0 m or as large as 12 m.

4. You are trying to cross a river that flows toward the south with a strong current. You start out in your motorboat on the east bank desiring to reach the west bank directly west from your starting point. You should head your motorboat *

in a general northwesterly direction.

5. For general projectile motion with no air resistance, the horizontal component of a projectile's acceleration *

is always zero.