1. [3335.66 Points] DETAILS PREVIOUS ANSWERS OSCOLPHYSZMSACC 5.1.P.004. Suppose you have a llZ-kg wooden crate resting on a wood floor. [For each answer, enter a number. \"k = 0.3 and In: 2 0.5) (a) What maximum force (in N} can you exert horizontally on the crate without moving it?I 548.8 y N {b} If you continue to exert this force (in m/sZ) once the crate sta rts to slip, what will the magnitude of its acceleration (in mfsz] then be? 329.23 x mis2 Submit An swer 2. [016.66 Points] DETAILS PREVIOUS ANSWERS OSCOLPHYSZO16ACC 5.1.P.018. A contestant in a winter games event pushes a 33.0 kg block of ice across a frozen lake as shown in the gure below. The coefficient of static friction is 0.1 and the coefcient of kinetic friction is 0.03. (For each answer, enter a number.) (a) Calculate the minimum force F (in N] he must exert to get the block moving. mm {b} What is its acceleration (in m/sz) once it starts to move, if that force is maintained? at mfsz 3. [16.66 Points] TAILS OSCOLPHYSZO16ACC 5c2.P.020. MY NOTES ASK YOUR TEACHER The terminal velocity of a person tailing in air depends upon the weight and the area of the person tacing the fluid. Find the terminal velocity (in meters per second and kilometers per hour) of a 95.0 kg skydlver tailing in a pike (headtnst) position with a surtace area oi 0.1m m2. (Assume that the density of air is 1.21 kg/m3 and the drag coefcient ota skydiver in a pike position is 0.7. For each answer. enter a number.) PRACTlCE ANOTHER terminal velunty in rn/e m/s terminal veludty in km/h km/h t SubmitAnswer 4. [16.66 Paints] OSCOLPHVSZD16ACC Gc1.P.DO1. MY NOTES ASK VOUR TEACHER FRACTlCE ANOTHER Semi-trailer trucks have an odometer on one hub of a trailer wheel. The hub is weighted so that it does not rotate, but it contains gears to count the number of wheel revolutionsit then calculates the distance traveled. lfthe wheel has a 1.17 m diameter and goes through 220.000 rotations, how many kilometers should the odometer read? (Enter a number.) km SubmitAnswer 5. [16.66 Points] DETAILS OSCOLPHVSZMSACC 6c2.P.D15. MY NOTES ASK YOUR TEACHER FRACTlCE ANOTHER Helicopter plades Withstand tremendous stresses. in addition to supporting the weight or a helicopter, they are spun at rapid rates and experience large centripetal accelerations, especially at the tip. (For each answer, enter a number.) (a) calculate the magnitude [in nil/51) nfthe centripetal acceleration stthe tip Ma 3 7a m long helicopter blade that rotates at 295 rev/min. S me? (p) Compare the linear speed of the tip with the speed of sound (taken to he 340 m/s). via/venom : E 6. [-lEJ Points] OSCOLPHYS2U16ACC E.3.P.023. I MY NOTES (a) A 190 kg child is riding a playground merryigoiround that is rotating at 450 revlmin. What centripetal force (in N] must she exert to stay on if she is 200 m from its center? (Enter a number] N (b) What centripetal force (in N) does she need to stay on an amusement park merry-go-round that rotates at 3.00 revfmin if she is 5.0:) m from its center? (Enter a number.) N (c) Compare each force with her weight. (For each answer, enter a number.) [force from (a))f(weight) = |:| [force from (mmweight) = :l 1. [-/5.71 Points] DETAILS OSCOLPHYS2016ACC 7.1.P.001. MY NOTES ASK YOUR TEACHER How much work does a supermarket checkout attendant do on a can of soup he pushes 0.770 m horizontally with a force of 4.20 N? Express your answer in joules and kilocalories. (For each answer, enter a number.) work in joules work in kilocalories kcal Submit Answer 2. [-/5.71 Points] DETAILS OSCOLPHYS2016ACC 7.1.P.006. MY NOTES ASK YOUR TEACHER How much work (in ]) is done by the boy pulling his sister 36 m in a wagon as shown in the figure below? F 30 d OO Assume no friction acts on the wagon. (Assume d = 36 m and F = 49 N. Enter a number.) W = 1 Submit Answer3. [-/5.71 Points] DETAILS OSCOLPHYS2016ACC 7.1.P.004. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Suppose a car travels 108 km at a speed of 30.0 m/s, and uses 1.80 gallons of gasoline. Only 30% of the gasoline goes into useful work by the force that keeps the car moving at constant speed despite friction. (The energy content of gasoline is 1.30 x 10 ] per gallon.) (a) What is the force (in N) exerted to keep the car moving at constant speed? (Enter a number.) N (b) If the required force is directly proportional to speed, how many gallons will be used to drive 108 km at a speed of 28.0 m/s? (Enter a number.) gallons Submit Answer 4. [-/5.71 Points] DETAILS OSCOLPHYS2016ACC 7.2.P.015. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Using energy considerations, calculate the average force (in N) a 65.0 kg sprinter exerts backward on the track to accelerate from 2.00 to 7.00 m/s in a distance of 25.0 m, if he encounters a headwind that exerts an average force of 30.0 N against him. (Enter a number.) N Submit Answer 5. [-/5.71 Points] DETAILS OSCOLPHYS2016ACC 7.2.P.013. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A car's bumper is designed to withstand a 5.76 km/h (1.6 m/s) collision with an immovable object without damage to the body of the car. The bumper cushions the shock by absorbing the force over a distance. Calculate the magnitude of the average force (in N) on a bumper that collapses 0.195 m while bringing a 890 kg car to rest from an initial speed of 1.6 m/s. (Enter a number.) IN3. [-/5.71 Points] DETAILS OSCOLPHYS2016ACC 7.1.P.004. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Suppose a car travels 108 km at a speed of 30.0 m/s, and uses 1.80 gallons of gasoline. Only 30% of the gasoline goes into useful work by the force that keeps the car moving at constant speed despite friction. (The energy content of gasoline is 1.30 x 10 ] per gallon.) (a) What is the force (in N) exerted to keep the car moving at constant speed? (Enter a number.) N (b) If the required force is directly proportional to speed, how many gallons will be used to drive 108 km at a speed of 28.0 m/s? (Enter a number.) gallons Submit Answer 4. [-/5.71 Points] DETAILS OSCOLPHYS2016ACC 7.2.P.015. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Using energy considerations, calculate the average force (in N) a 65.0 kg sprinter exerts backward on the track to accelerate from 2.00 to 7.00 m/s in a distance of 25.0 m, if he encounters a headwind that exerts an average force of 30.0 N against him. (Enter a number.) N Submit Answer 5. [-/5.71 Points] DETAILS OSCOLPHYS2016ACC 7.2.P.013. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A car's bumper is designed to withstand a 5.76 km/h (1.6 m/s) collision with an immovable object without damage to the body of the car. The bumper cushions the shock by absorbing the force over a distance. Calculate the magnitude of the average force (in N) on a bumper that collapses 0.195 m while bringing a 890 kg car to rest from an initial speed of 1.6 m/s. (Enter a number.) IN6. [-/5.71 Points] DETAILS OSCOLPHYS2016ACC 7.3.P.017. MY NOTES ASK YOUR TEACHER PRA (a) How much gravitational potential energy (in ]) (relative to the ground on which it is built) is stored in an Egyptian pyramid, given its mass is about 7 x 10 kg and its center of mass is 30.0 m above the surrounding ground? (Enter a number.) (b ) What is the ratio of this energy to the daily food intake of a person (1.2 x 10' ])? (Enter your answer as a ratio to the number 1. Enter a number.) : 1 Submit Answer 7. [-/5.74 Points] DETAILS OSCOLPHYS2016ACC 7.3.P.016. MY NOTES ASK YOUR TEACHER PRA A hydroelectric power facility converts the gravitational potential energy of water behind a dam to electric energy. (For each answer, enter a number.) (a) What is the gravitational potential energy (in ]) relative to the generators of a lake of volume 43.0 km (mass = 4.30 x 1015 kg), given that the lake has an average height of 39.0 m above the generators? (b) Compare this with the energy stored in a 9-megaton fusion bomb. Elake/Ebomb = + Submit