It's possible for a determined group of people to pull an aircraft. drag is negligible at low speeds, and the only force impeding motion is the rolling friction of the rubber tires on the concrete runway. in 2000, a team of 60 british police officers set a world record by pulling a boeing 747, with a mass of 200,000 kg, a distance of 100 m in 53 s. the plane started at rest. suppose that μr=0.02. estimate the force with which each officer pulled on the plane, assuming constant pulling force and constant acceleration.

Amass m = 74 kg slides on a frictionless track that has a drop, followed by a loop-the-loop with radius r = 18.4 m and finally a flat straight section at the same height as the center of the loop (18.4 m off the ground). since the mass would not make it around the loop if released from the height of the top of the loop (do you know why? ) it must be released above the top of the loop-the-loop height. (assume the mass never leaves the smooth track at any point on its path.) 1. what is the minimum speed the block must have at the top of the loop to make it around the loop-the-loop without leaving the track? 2. what height above the ground must the mass begin to make it around the loop-the-loop? 3. if the mass has just enough speed to make it around the loop without leaving the track, what will its speed be at the bottom of the loop? 4. if the mass has just enough speed to make it around the loop without leaving the track, what is its speed at the final flat level (18.4 m off the ground)? 5. now a spring with spring constant k = 15600 n/m is used on the final flat surface to stop the mass. how far does the spring compress?