vectors, velocity

Hi. I'm not sure how to do this problem. "Romeo is chucking pebbles as gently as he can up to Juliet's window. That is, he wants the pebbles to hit the window with the least possible speed, as shown in the figure below. (See attached Word file.) He is standing at the edge of a rose garden at H = 7.40 m below her window and ...continues

vectors, distance

Hi. This following problem has me completely confused. Can you please give me a step by step rundown of how to do it? Thank you! "A rescue plane wants to drop supplies to isolated mountain climbers on a rocky ridge H = 227 m below. If the plane is traveling horizontally with a speed of 223 km/hr (61.9 m/s), how far in adva ...continues

vectors, velocity

Hi. I'm confused about the following problem: "A student stands at the edge of a cliff and throws a stone horizontally over the edge with a speed of v(0) = 17.4 m/s. The cliff is h = 42.4 m above a flat horizontal beach. With what speed does it land?" (There's a drawing attached in a Word file if you want to see it.) I ...continues

Gravitation, central force.

A particle at reast is attracted toward a center of force according to the relation F=-mk^2/x^33. Calculate the time required for the particle to reach the force center from a distance d.

hydraulic jack problem

A hydraulic jack has two pistons. The diameters of the larger piston and smaller piston are 15 cm and 1.25 cm respectively.It is necessary to lift a 2000 pound car. How large a force must be applied to the small piston? Now assume that a small piston moves through a distance of 10 cm. By what distance will the large piston move?

Surface tension problem

At 20 degrees celsius the surface tensions for water and mercury are 73dyn/cm and 470dyn/cm respectively. Find these values in SI units. A small capillary tube of 1mm diameter is placed into a container of 20 degree celsius water. will the level of the water in the tube move above or below the level of water? by what distance in ...continues

Vectors

Hi. Can someone show me how to do this problem? I'm not sure how to factor in the 40.1 m/s. "A firefighter, 48.2 m away from a burning building, directs a stream of water from a ground level fire hose at an angle of 32.8 degrees above the horizontal. If the speed of the stream as it leaves the hose is 40.1 m/s, at what height ...continues

Average force

Hi. I'm not sure how to do the following problem: "A 0.139 baseball traveling 46.6 m/s strikes the catcher's mit, which, in bringing the ball to a rest, recoils backward 11.1 cm. What was the average force applied by the ball on the glove?" I know, of course, that F = ma. But I'm not sure how to factor in the 11.1 cm. I'm ...continues

Vectors, velocity & mass

Hi. I can't figure out the following problem: "Six model rockets (ABCDEF) have just had their engines turned off. All of the rockets are aimed at the same angle, but their speeds differ. All of the rockets are the same size and shape, but they carry different loads, so their masses differ. (Their respective masses are listed ...continues

Eeasy vector question

Hi. Okay here's an easy one. (And still I can't get it. Ugh.) I've put more credits on it than I normally would, hoping that one of you who spent a lot of time on my posting PC9039 can recoup some more for the effort you spent on that problem. (I'm sorry about that -- I didn't realize the problem was that difficult. I figured I ...continues