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

Kinetic friction

Hi. Can you tell me how to do the following problem? I can't find an applicable equation for it, or a similar problem in my book. "A box is given a push so that it slides across the floor. How far will it go, given that the coefficient of kinetic friction is 0.190 and the push imparts an initial speed of 4.20 m/s?" Thank y ...continues

Vector, projectile

Hi. More vector confusion. "A catapult on a cliff launches a large round rock towards a ship from a H of 33.0 m above sea level, directed at an angle above the horizontal with an unknown speed v(0). The projectile remains in flight for 6.00 seconds and travels a horizontal distance D of 169 m. Assuming that air friction can b ...continues

Contact force

Hi. Here's my problem: "Two blocks, M1 and M2, are in contact on a frictionless table. A horizontal force F is applied to M2. If M1 = 1.30 kg, M2 = 3.20 kg, and F = 5.30 N, find the size of the contact force between the two blocks." I know that I first need to treat the blocks as one body and find the acceleration, so... ...continues

Force, speed

Hi. Here's a tricky one (for me, anyway): "A train has a mass of 5.07 x 10^6 kg and is moving at 75.5 km/hr. The engineer applies the brakes, which results in a net backward force of 1.71 x 10^6 N on the train. The brakes are held on for 26.0 s. What is the new speed of the train?" Thank you!

Force of friction

A 17.2 kg box is released on a 38.1 degree incline and accelerates down the incline at 0.269 m/s^2. Find the friction force impeding its motion, and the coefficient of friction.