Concept explainers
A bullet is fired upward with a speed v0 from the edge of a cliff of height h (Fig. P3.22). (a) What is the speed of the bullet when it passes by the cliff on its way down? (b) What is the speed of the bullet just before it strikes the ground? (c) If the bullet is instead fired downward with the same initial speed v0, what is its speed just before it strikes the ground? Express your answers in terms of v0, h, and g. Ignore air drag. Assume the bullet is fired straight up in (a) and (b) and straight down in (c).
A ball is thrown upward with a speed of 35 m/s from the edge of a cliff of height h = 15 m (similar to Fig. P3.22). (a) What is the speed of the ball when it passes by the cliff on its way down to the ground? (b) What is the speed of the ball when it hits the ground? Ignore air drag. Assume the ball is thrown straight up.
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College Physics, Volume 1
- A landscape architect is planning an artificial waterfall in a city park. Water flowing at 1.70 m/s will leave the end of a horizontal channel at the top of a vertical wall h = 2.35 m high, and from there it will fall into a pool (Fig. P3.42). (a) Will the space behind the waterfall be wide enough for a pedestrian walkway? (b) To sell her plan to the city council, the architect wants to build a model to standard scale, which is one-twelfth actual size. How fast should the water flow in the channel in the model? Figure P3.42arrow_forwardAn attacker at the base of a castle wall 3.75 m high throws a rock straight up with speed 7.50 m/s from a height of 1.60 m above the ground. (a) Will the rock reach the top of the wall? Yes No (b) If so, what is its speed at the top? If not, what initial speed must it have to reach the top? m/s Enter a number. (c) Find the change in speed of a rock thrown straight down from the top of the wall at an initial speed of 7.50 m/s and moving between the same two points. m/s (d) Does the change in speed of the downward-moving rock agree with the magnitude of the speed change of the rock moving upward between the same elevations? Yes No (e) Explain physically why it does or does not agree.arrow_forwardA basketball is tossed vertically up into the air from the edge of a roof 8.5 m above the ground. First, if the ball took 1.6 seconds from the point when released upward until it hit the ground, what was the ball's initial speed? Second, what was the greatest height reached by the ball with respect to the roof? Ignore air resistance and use a value of g = 10.0 m/s when answering this question. B IU A + v ... Paragraph 65% 72°F $C# ス liliarrow_forward
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- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning