**Particle Models in Two Dimensions****Practice Problems**

**Problem 1:**A shotput is thrown. For the each of the indicated positions of the shotput along its trajectory, draw and label the following vectors: the x-component of the velocity, the y-component of the velocity, and the acceleration. Explain why you drew the vectors as you did.

**Problem 2: **A rock is thrown with an initial vertical
velocity component of 30 m/s and an initial horizontal velocity
component of 40 m/s.

a. What will these velocity components be one second after the rock reaches the top of its path?

b. Assuming the launch and landing heights are the same, how long will the rock be in the air?

c. Assuming the launch and landing heights are the same, how far will the rock land from where it was thrown?

a. Which ball will have the greater acceleration while in flight? Explain your reasoning.

b. Which ball will hit farther from the base of the building? Explain your reasoning.

c. Which ball will reach a greater maximum height? Explain your reasoning.

d. Which ball will be going faster just before hitting the street? Explain your reasoning.

e. How could you adjust only the angle of the upper launcher so that the ball hits in the same place as the ball from the lower launcher? Explain your reasoning.

f. How could you adjust only the angle of the lower launcher so that the ball hits in the same place as the ball from the upper launcher? Explain your reasoning.

adapted from *Qualitative Problems for Introductory Physics*
by Robert Gibbs

a. Which ball has a greater initial vertical component of velocity? Explain.

b. Which ball has a greater initial horizontal component of velocity? Explain.

c. Which ball has the larger launch angle? Explain.

d. Which ball has greater acceleration while in flight? Explain.

e. Which ball will land farther from the launchers? Explain.

f. Which ball takes longer to reach maximum height? Explain.

g. If the balls were launched simultaneously, would they collide before landing? Explain.

adapted from *Qualitative Problems for Introductory Physics*
by Robert Gibbs

**Problem 7:**A daredevil tries to jump a canyon of width 10 m. To do so, he drives his motorcycle up an incline sloped at an angle of 15 degrees. What minimum speed is necessary to clear the canyon?