For this homework, carefully study Examples 3.4 and 3.5 from the textbook, found in the section 3.4, Projectile Motion:

Now work on them with different initial velocity:

v0 = 100 m/s

at an angle 45o above horizon. 

Use g = -10.0 m/s as the gravitational acceleration instead of g = -9.8 m/s.


In other words, work on the following problems.

[1] During a fireworks display, a shell is shot into the air with an initial speed of 100 m/s at an angle of 45.0º above the horizontal, as illustrated in Figure 3.38. The fuse is timed to ignite the shell just as it reaches its highest point above the ground. (a) Calculate the height at which the shell explodes. (b) How much time passed between the launch of the shell and the explosion? (c) What is the horizontal displacement of the shell when it explodes?

[2] Kilauea in Hawaii is the world’s most continuously active volcano. Very active volcanoes characteristically eject red-hot rocks and lava rather than smoke and ash. Suppose a large rock is ejected from the volcano with a speed of 100 m/s and at an angle 45.0º above the horizontal, as shown in Figure 3.39. The rock strikes the side of the volcano at an altitude 20.0 m lower than its starting point. (a) Calculate the time it takes the rock to follow this path. (b) What are the magnitude and direction of the rock’s velocity at impact?

Again, use g = -10.0 m/s.

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