A tadpole swims across a pond at 3.50 cm/s. The tail of the tadpole exerts a force of 28.0 mN to overcome drag forces exerted on the tadpole by the water.

A 60.0 kg skier with an initial speed of 14 m/s coasts up a 2.50 m high rise as shown in the figure. Find her final speed right at the top, in meters per second, given that the coefficient of friction between her skis and the snow is 0.39.

A 4.25 kg block is projected at 5.40 m/s up a plane that is inclined at 30.0° with the horizontal. The block slides some distance up the incline, stops turns around and slides back down to the bottom. When it reaches the bottom of the incline again, it is traveling with a speed of 3.80 m/s. If the coefficient of kinetic friction between the block and the plane is 0.500, how far up the incline did the block slide?

A girl on a skateboard (total mass of 33.6 kg) is moving at a speed of 12.0 m/s at the bottom of a long ramp. The ramp is inclined at 23° with respect to the horizontal. If she travels 14.1 m upward along the ramp before stopping, what is the net frictional force on her?

A segment of DNA is put in place and stretched. Figure P7.82 shows a graph of the force exerted on the DNA as a function of the displacement of the stage. Based on this graph, which statement is the best interpretation of the DNA’s behavior over this range of displacements? The DNA (a) does not follow Hooke’s law, because its force constant increases as the force on it increases; (b) follows Hooke’s law and has a force constant of about 0.1 pN/nm; (c) follows Hooke’s law and has a force constant of about 10 pN/nm; (d) does not follow Hooke’s law, because its force constant decreases as the force on it increases.

A stone with a weight of 5.41 N is launched vertically from ground level with an initial speed of 21.0 m/s, and the air drag on it is 0.263 N throughout the flight. What are (a) the maximum height reached by the stone and (b) its speed just before it hits the ground? (a) Number i Units (b) Number Units

You have been asked by your supervisors at A&L Engineering to design a roller coaster for a new theme park. Because this design is in the initial stages, you have been asked to create a track for the ride. Your coaster should have at least two peaks and two valleys, and launch from an initial height of 75 meters. Each peak and valley should represent a vertical change of at least 20 meters. In your design, you should plan for a mass between 400 and 600 kilograms.   Unless otherwise stated, you can ignore the effects of friction. Following your calculations, you have been asked to describe the energy transfers detailed by these equations.   For these calculations, assume that the cart will inelastically collide with a cart of equal mass at rest on a flat surface.   Calculate the momentum and kinetic energy of the cart before and after an inelastic collision. In your calculations, be sure to explicitly state the equations you use and what values you will be substituting to calculate…

At the start of a race, a four-man bobsled team pushes their sled as fast as they can along a 50 m flat starting stretch. The net force that the four men together apply to the 325 kg bobsled is 80.093 N directed at 15 degrees below the horizontal. As they push, 60 N of kinetic friction opposes them. What is the speed of the sled right before the team jumps on the sled?

A 86.0 kg diver steps off a 10.0 m high diving board and drops, from rest, straight down into the water. If he comes to rest 7.20 m beneath the surface of the water, determine the average resistive force exerted by the water.