force, cycling up hill

"If a bicyclist of mass 69.0 (including the bicycle) can coast down a 6.90 degree hill at a steady speed of 5.60 km/hr because of air resistance, how much force must be applied to climb the hill at the same speed?"

force, pulley system

"The leg and cast in the figure below (see attached Word file) weigh 217 N (w1). (Assume w3 = 100 N and theta = 39.3°). Determine the weight w2 needed in order that there be no force exerted on the hip joint by the leg plus cast."

force, weight in moving elevator

A 75.6 kg person stands on a scale in an elevator. What does the scale read (it reads mass units, not weight units) when the elevator is accelerating downward at 3.00 m/s^2?"

force, acceleration, coefficient of kinetic friction

"In the figure below, m1 = 10.7 kg and m2 = 4.15 kg. The coefficient of kinetic friction is 0.271. If the system is set in motion with m2 moving downward, what will be the acceleration of the system?" I'm not sure how to factor in the coefficient of kinetic friction. Can you show me how to do this problem? Thank you!

force

"A student's car stalls right in front of a speed bump while she is on her way to physics class. To pull it over the bump, she ties a cable to her bumper and to a nearby tree, and pulls with a force, F, of 70.0 pounds (311 N) at the midpoint in a perpendicular direction. If theta is 12.4 degrees, what is the size of the force pu ...continues

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