force of air resistance

"A fire helicopter carries a 607 kg bucket of water at the end of a 17.4 m long cable. Flying back from a fire at a constant speed of 35.3 m/s, the cable makes an angle of 41.6° with respect to the vertical. Determine the force of air resistance on the bucket."

force, velocity

"A 5.06 kg block located on a horizontal floor is pulled by a cord that exerts a force F = 13.9 N at an angle theta = 18.0° above the horizontal, as shown in the figure. The coefficient of kinetic friction between the block and the floor is 0.06. What is the speed of the block 3.5 s after it starts moving?" A picture is att ...continues

friction, static and kinetic

Hi. Can you show me how to do the following problem? "A box of mass m1 sits on a table. It is connected, by a rope drawn through a pulley, to a box m2 (where m2 = 2.10 kg) that is hanging off the side of the table. (Note that box m2 does not touch the table in any way.) The coefficient of static friction between mass m1 and t ...continues

centrifuge rotation

"How fast (in rpm) must a centrifuge rotate if a particle 8.06 cm from the axis of rotation is to experience an acceleration of 79000 g?"

rotating turntables

Hi. Can you help me with the following problem? I thought the answer was BE, but it's not, and I'm not sure why not. "Six blocks are sitting at rest on rotating turntables. All of the turntables have the same rotation rate (i.e., the same frequency). The masses of the blocks and how far out from the center they sit varies. Th ...continues

max tangential speed

Hi. Can you please show me how to do the following problem? "A mass M of 2.71 kg is attached to the end of a string whose length is 0.640 m. The mass slides without friction on a horizontal surface. If the string can withstand a maximum tension of 77.1 N, what is the maximum tangential speed the ball can have before the strin ...continues

car making circular turn

Hi. Can you show me how to do the following problem? "A 1990 kg car rounds a circular turn of radius 21.2 m. If the road is flat and the coefficient of friction between tires and road is 0.710, how fast can the car go without skidding?" I know the first step is to calculate the normal friction: F(N) = mg = (1990 kg)(9.8 ...continues

rotational speed in rpm

Hi. Can you please show me how to do the following problem? "A device for training astronauts and jet fighter pilots is designed to rotate the trainee in a horizontal circle of radius 11.0 m. If the force felt by the trainee is 7.91 times her own weight, how fast is she rotating, in revolutions per second?" Thank you!

speed of object in revolutions around a circle

Hi. Can you please help me with the following problem? "A puck of mass 0.270 kg is tied to a string and allowed to revolve in a circle of radius 1.09 m on a frictionless horizontal table. The other end of the string passes through a hole in the center of the table, and a mass of 1.24 kg is tied to it (see figure in attached W ...continues

angel theta from horizontal circle

Hi. Can you please show me how to do the following problem? It has me completely confused. "A mass m = 9.100 kg is suspended from a string of length L = 1.510 m. It revolves in a horizontal circle as shown. The tangential speed of the mass is 2.850 m/s. What is the angle theta between the string and the vertical (in degrees)? ...continues