A scuba diver makes a slow descent into the depths of the ocean. His vertical position with respect to a boat on the surface changes several times. He makes the first stop 9.0 m from the boat but has a problem with equalizing the pressure, so he ascends 3.0 m and then continues descending for another 12.0 m to the second stop. From there, he ascends 4 m and then descends for 18.0 m, ascends again for 7 m and descends again for 24.0 m, where he makes a stop, waiting for his buddy. Assuming the positive direction up to the surface, express his net vertical displacement vector in terms of the unit vector. h vector = −100 m û h vector = +50 m û h vector = +100 m û h vector = −49 m û
A scuba diver makes a slow descent into the depths of the ocean. His vertical position with respect to a boat on the surface changes several times. He makes the first stop 9.0 m from the boat but has a problem with equalizing the pressure, so he ascends 3.0 m and then continues descending for another 12.0 m to the second stop. From there, he ascends 4 m and then descends for 18.0 m, ascends again for 7 m and descends again for 24.0 m, where he makes a stop, waiting for his buddy. What is his distance to the boat? 100 m 49 m 55 m 52 m
In a tug-of-war game on one campus, 15 students pull on a rope at both ends in an effort to displace the central knot to one side or the other. Two students pull with force 196 N each to the right, four students pull with force 98 N each to the left, five students pull with force 62 N each to the left, three students pull with force 150 N each to the right, and one student pulls with force 250 N to the left. Assuming the positive direction to the right, express the net pull on the knot in terms of the unit vector. F vector = −200 N û F vector = 150 N û F vector = −110 N û F vector = 50 Nû
An adventurous dog strays from home, runs three blocks east, two blocks north, one block east, one block north, and two blocks west. Assuming that each block is about 100 m, how far from home and in what direction is the dog? 360 m, 56 degrees 300 m, 66 degrees 360 m, 86 degrees 460 m, 56 degrees
A small plane flies 40.0 km in a direction 60 degrees north of east and then flies 30.0 km in a direction 15 degrees north of east. Find the total distance the plane covers from the starting point and the direction of the path to the final position. 64.8 km, 60 degrees, north of east 54.8 km, 60 degrees, north of east 54.8 km, 40.9 degrees, north of east 64.8 km, 40.9 degrees, north of east
A surveyor measures the distance across a river that flows straight north by the following method. Starting directly across from a tree on the opposite bank, the surveyor walks 100 m along the river to establish a baseline. She then sights across to the tree and reads that the angle from the baseline to the tree is 35 degrees. How wide is the river? 90 m 50 m 100 m 70 m
A delivery man starts at the post office, drives 40 km north, then 20 km west, then 60 km northeast, and finally 50 km north to stop for lunch. How far is the restaurant from the post office? R = 225 mi R = 250 mi R = 300 mi R = 134.32 mi
A delivery man starts at the post office, drives 40 km north, then 20 km west, then 60 km northeast, and finally 50 km north to stop for lunch. Find his net displacement vector. R vector −(22.43 i+232.43 j)mi R vector - (52.45 i +102.55 j)mi R vector - ( 22.43 i+132.43 j)mi R vector - (56.53 i +923.25 j) mi
Assuming the +x-axis is horizontal to the right for the vectors in the following figure, find the following scalar products: D vector . C vector −331 −111 −200 −221
Assuming the +x-axis is horizontal to the right for the vectors in the following figure, find the following scalar products: A vector. C vector 22 10 2 0
Suppose you walk 18.0 m straight west and then 25.0 m straight north. How far are you from your starting point? 40.0 m 30.8 m 60.0 m 80.0 m
A delivery man starts at the post office, drives 40 km north, then 20 km west, then 60 km northeast, and finally 50 km north to stop for lunch. Find his net displacement vector. 80 km, 80 degrees 134 km, 80 degrees 100 km, 70 degrees 140 km, 90 degrees
A delivery man starts at the post office, drives 40 km north, then 20 km west, then 60 km northeast, and finally 50 km north to stop for lunch. What is his compass heading on the return trip? Assume the +x-axis is to the east. 100 degrees south of west 90 degrees south of west 120 degrees south of west 80.2 degrees south of west
The coordinates of a particle in a rectangular coordinate system are (1.0, −4.0, 6.0). What is the position vector of the particle? r vector = 6.0 i^−4.0 j^+4.0 k^ r vector = 4.0 i^−1.0 j^+6.0 k^ rvector = −4.0 i^−1.0 j∧+6.0 k^ rvector = 1.0 i^−4.0 j^+6.0 k^
The position of a particle changes from r1 = (2.0 i^+3.0 j^)cm to r2 = (−4.0 i^+3.0 j^)cm. What is the particle's displacement? r2^−r1^ = −3.0 i^cm r1^−r2^ = +6.0 i^cm r2^−r1^ = −9.0 i^cm r2^−r1^ = −6.0 i∧cm
A Lockheed Martin F-35 II Lighting jet takes off from an aircraft carrier with a runway length of 90 m and a takeoff speed 70 m/s at the end of the runway. Jets are catapulted into airspace from the deck of an aircraft carrier with two sources of propulsion: the jet propulsion and the catapult. At the point of leaving the deck of the aircraft carrier, the F-35's acceleration decreases to a constant acceleration of 5.0 m/s2 at 30∘ with respect to the horizontal. How far has it traveled horizontally? 340.0 m 403.8 m 203.8 m 300.0 m
A Lockheed Martin F-35 II Lighting jet takes off from an aircraft carrier with a runway length of 90 m and a takeoff speed 70 m/s at the end of the runway. Jets are catapulted into airspace from the deck of an aircraft carrier with two sources of propulsion: the jet propulsion and the catapult. At the point of leaving the deck of the aircraft carrier, the F-35's acceleration decreases to a constant acceleration of 5.0 m/s2 at 30∘ with respect to the horizontal. At what altitude is the fighter 5.0 s after it leaves the deck of the aircraft carrier? 41.50 m 31.25 m 20.50 m 50.0 m
A bullet is shot horizontally from shoulder height (1.5 m) with an initial speed 200 m/s. (a) How much time elapses before the bullet hits the ground? (b) How far does the bullet travel horizontally? (A) a) 0.55 s b) 110 m (B) a) 0.39 s b) 78 m (C) a) 0.31 s b) 61 m (D) a) 0.28 s b) 55 m
A bullet is shot horizontally from shoulder height (1.5 m) with an initial speed 200 m/s. How much time elapses before the bullet hits the ground? 0.25 s 0.45 s 0.55 s 0.30 s
A particle travels in a circle of radius 10 m at a constant speed of 20 m/s. What is the magnitude of the acceleration? 60 m/s^2 30 m/s^2 20 m/s^2 40 m/s^2
A flywheel is rotating at 30 rev/s. What is the total angle, in radians, through which a point on the flywheel rotates in 40 s? 2400 pi rad 1400 pi rad 1000 pi rad 2000 pi rad
A seagull can fly at a velocity of 9.00 m/s in still air. If it takes the bird 20.0 min to travel 6.00 km straight into an oncoming wind, what is the velocity of the wind? -4.0 m/s -8 m/s -3 m/s -2 m/s
Raindrops fall vertically at 4.5 m/s relative to the earth. What does an observer in a car moving at 22.0 m/s in a straight line measure as the velocity of the raindrops? The rain is coming from 20.5 degrees north of east The rain is coming from 11.6 degrees north of east The rain is coming from 15.3 degrees north of east The rain is coming from 10.5 degrees east of north
A Lockheed Martin F-35 II Lighting jet takes off from an aircraft carrier with a runway length of 90 m and a takeoff speed 70 m/s at the end of the runway. Jets are catapulted into airspace from the deck of an aircraft carrier with two sources of propulsion: the jet propulsion and the catapult. At the point of leaving the deck of the aircraft carrier, the F-35's acceleration decreases to a constant acceleration of 5.0 m/s2 at 30∘with respect to the horizontal. What is the initial acceleration of the F-35 on the deck of the aircraft carrier to make it airborne? 20.0 m/s^2 35.0 m/s^2 27.2 m/s^2 30.0 m/s^2
A bullet is shot horizontally from shoulder height (1.5 m) with an initial speed 200 m/s. How far does the bullet travel horizontally? 220 m 110 m 150 m 80 m
A marble rolls off a tabletop 1.0 m high and hits the floor at a point 3.0 m away from the table's edge in the horizontal direction. How long is the marble in the air? 0.60 s 0.50 s 0.55 s 0.45 s
Cam Newton of the Carolina Panthers throws a perfect football spiral at 8.0 rev/s. The radius of a pro football is 8.5 cm at the middle of the short side. What is the centripetal acceleration of the laces on the football? 220 m/s^2 314 m/s^2 200 m/s^2 214.0 m/s^2
To start a car engine, the car battery moves 3.75×1021 electrons through the starter motor. How many coulombs of charge were moved? Negative charge of an electron = 1.602×10−19 C -200.5 C −800.5 C −400.0 C −600.8 C
Common static electricity involves charges ranging from nanocoulombs to microcoulombs. How many electrons must be removed from a neutral object to leave a net charge of 0.500 μC ? Negative charge of an electron = 1.602×10−19 C 2.122×10^12 electrons 3.121×10^12 electrons 8.321×10^12 electrons 4.521×10^12 electrons
If 1.80×1020 electrons move through a pocket calculator during a full day's operation, how many coulombs of charge moved through it? Negative charge of an electron = 1.602×10−19 C −30.52 C −20.30 C −28.84 C 55.05 C
A 50.0-g ball of copper has a net charge of 2.00 μC. What fraction of the copper's electrons has been removed? (Each copper atom has 29 protons, and copper has an atomic mass of 63.5. ) Atomic Mass Unit = 1.660×10-27 kg/u 10.000×10^23 atoms 9.09×10^-13 atoms 8.759×10^23 atoms 6.779×10^23 atoms
What net charge would you place on a 100-g piece of sulfur if you put an extra electron on 1 in 1012 of its atoms? (Sulfur has an atomic mass of 32.1 u. Atomic Mass Unit = 1.660×10-27 kg/u Negative charge of an electron = 1.602×10-19 C 30 micro Coulomb 20 micro Coulomb 90 micro Coulomb 60 micro Coulomb
An amoeba has 1.00×1016 protons and a net charge of 0.300 pC. How many fewer electrons are there than protons? Negative charge of an electron = 1.602×10-19 C 3.873×10^6 e 1.873×10^6 e 2.873×10^10 e 4.873×10^6 e
Protons in an atomic nucleus are typically 10−15 m apart. What is the electric force of repulsion between nuclear protons? Negative charge of an electron = 1.602×10−19 C 255.0 N 250.7 N 230.7 N 330.0 N
A particle of charge 2.0×10-8 C experiences an upward force of magnitude 4.0×10-6 N when it is placed in a particular point in an electric field. What is the electric field at that point? 4.0×10^2 N/C up 2.0×10^2 N/C up 4.0×10^2 N/C down 2.0×10^2 N/C down
A thin conducting plate 1.0 m on the side is given a charge of −2.0×10−6 C. An electron is placed 1.0 cm above the center of the plate. What is the acceleration of the electron? Negative charge of an electron = 1.602×10−19 C Mass of an electron = 9.11×10^−31 kg 4.05×10^16 m/s^2 6.05×10^16 m/s^2 2.04×10^16 m/s^2 4.04×10^16 m/s^2
Which of the following electric field lines are incorrect for point charges? (a) (c) (e) (b) (d) (f) (g) b, c, d, f, g All are correct a, b, c, d, f, g a, c, d, f, g
Find the tension in each of the three cables supporting the traffic light if it weighs 2.00×102 N. T1 = 80.6 N, T2 = 200 N, T3 = 4.00×10^2 N T1 = 93.6 N, T2 = 156 N, T3 = 2.00×10^2 N T1 = 85.6 N, T2 = 256 N, T3 = 6.00×10^2 N T1 = 75.5 N, T2 = 320 N, T3 = 4.00×10^2 N
A 35.0−kg dolphin decelerates from 12.0 to 7.50 m/s in 2.30 s to join another dolphin in play. What average force was exerted to slow the first dolphin if it was moving horizontally? (The gravitational force is balanced by the buoyant force of the water. ) −80.0 N +75.0 N −68.5 N +90.0 N
A flea jumps by exerting a force of 1.20×10−5 N straight down on the ground. A breeze blowing on the flea parallel to the ground exerts a force of 0.500×10−6 N on the flea while the flea is still in contact with the ground. Find the direction and magnitude of the acceleration of the flea if its mass is 6.00×10−7. Do not neglect the gravitational force. 10.2 m/s^2 at 4.67 degrees from vertical 12.5 m/s^2 at 5.60 degrees from vertical 15.2 m/s^2 at 6.67 degrees from vertical 20.2 m/s^2 at 9.55 degrees from vertical
A contestant in a winter sporting event pushes a 45.0−kg block of ice across a frozen lake as shown below. Calculate the minimum force F he must exert to get the block moving. (The coefficient of friction of ice static = 0.1 and kinetic = 0.03) 40.0 N 61.0 N 30.0 N 51.0 N
When rebuilding his car's engine, a physics major must exert 3.00×102 N of force to insert a dry steel piston into a steel cylinder. What is the normal force between the piston and cylinder? (Kinetic friction is 0.3 ) 3.00×10^3 N 2.00×10^3 N 1.00×10^3 N 5.00×10^3 N
Suppose you have a 120-kg wooden crate resting on a wood floor, with coefficient of static friction 0.500 between these wood surfaces. What maximum force can you exert horizontally on the crate without moving it? 988 N 488 N 788 N 588 N
A 22.0-kg child is riding a playground merry-go-round that is rotating at 40.0 rev/min. What centripetal force is exerted if he is 1.25 m from its center? 585 N 453 N 483 N 355 N
A machine at a post office sends packages out a chute and down a ramp to be loaded into delivery vehicles. Calculate the acceleration of a box heading down a 10.0∘ slope, assuming the coefficient of friction for a parcel on waxed wood is 0.100. 0.737 m/s^2 0.65 m/s^2 0.85 m/s^2 0.97 m/s^2
Suppose that the resistive force of the air on a skydiver can be approximated by f = -bv2. If the terminal velocity of a 50.0-kg skydiver is 60.0 m/s, what is the value of b? 0.46 kg/m 0.28 kg/m 0.14 kg/m 0.98 kg/m
A 30.0-kg girl in a swing is pushed to one side and held at rest by a horizontal force F so that the swing ropes are 30.0∘ with respect to the vertical. Calculate the magnitude of F. 170 N 150 N 250 N 200 N
Consider the 52.0-kg mountain climber shown below. Find the tension in the rope and the force that the mountain climber must exert with her feet on the vertical rock face to remain stationary. Assume that the force is exerted parallel to her legs. Also, assume negligible force exerted by her arms. 272 N, 512 N 450 N, 600 N 375 N, 600 N 475 N, 700 N
What is the ideal banking angle for a gentle turn of 1.20-km radius on a highway with a 105 km/h speed limit (about 65 mi/h ), assuming everyone travels at the limit? 6.2 degrees 4.14 degrees 3.55 degrees 5.22 degrees
Suppose a car travels 108 km at a speed of 30.0 m/s, and uses 2.0 gal 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 about 140 MJ/ gal. ) What is the magnitude of the force exerted to keep the car moving at constant speed? 666 N 650 N 778 N 888 N
A 75.0-kg person climbs stairs, gaining 2.50 m in height. Find the work done to accomplish this task. 3.00 KJ 4.20 KJ 2.50 KJ 1.84 KJ
How much work does a supermarket checkout attendant do on a can of soup he pushes 0.600 m horizontally with a force of 5.00 N? 5.00 J 4.00 J 3.00 J 2.00 J
Compare the kinetic energy of a 20,000-kg truck moving at 110 km/h with that of an 80.0-kg astronaut in orbit moving at 27,500 km/h. Astronaut's KE = 350 X Truck's KE Astronaut's KE = 550 X Truck's KE Astronaut's KE = 250 X Truck's KE Astronaut's KE = 450 X Truck's KE
Calculate the kinetic energy of an 80.-kg runner sprinting at 10. m/s 6.0 kJ 80 kJ 2.0 kJ 4.0 kJ
Calculate the kinetic energy of a 2000.0-kg automobile moving at 100.0 km/h 882 kJ 900 kJ 650 kJ 772 kJ
Calculate the force needed to bring a 950-kg car to rest from a speed of 90.0 km/h in a distance of 120 m (a fairly typical distance for a non-panic stop). 4.00 kN 3.00 kN 2.47 kN 6.00 kN
An 8.0-g bullet with a speed of 800 m/s is shot into a wooden block and penetrates 20 cm before stopping. What is the average force of the wood on the bullet? Assume the block does not move. 11.0 kN 14.2 kN 10.5 kN 12.8 kN
A sled starts from rest at the top of a snow-covered incline that makes a 22∘ angle with the horizontal. After sliding 75 m down the slope, its speed is 14 m/s. Use the work-energy theorem to calculate the coefficient of kinetic friction between the runners of the sled and the snowy surface. 0.33 0.26 0.45 0.15
A large household air conditioner may consume 15.0 kW of power. What is the cost of operating this air conditioner 3.00 h per day for 30.0 d if the cost of electricity is $0.110 per kW, h ? $100 $200 $178 $149
Consider a charge Q1 (+5.0 μC) fixed at a site with another charge Q2 (charge +3.0 μC, mass 6.0 μg ) moving in the neighboring space. If Q2 starts from rest from a point 4.0 cm from Q1, what will be its speed when it is 8.0 cm from Q1? (Note: Q1 is held fixed in its place. ) k = 9.00×109 N⋅m2/C2 3.5×10^4 m/s 1.2×10^4 m/s 2.4×10^4 m/s 4.4×10^4 m/s
To form a hydrogen atom, a proton is fixed at a point and an electron is brought from far away to a distance of 0.529×10-10 m, the average distance between proton and electron in a hydrogen atom. How much work is done? k = 9.00×109 N⋅m2 /C2 5.40×10^-18 J 2.36×10^-18 J 4.36×10^-18 J 6.55×10^-18 J
Consider a charge Q1 (+5.0 μC) fixed at a site with another charge Q2 (charge +3.0 μC, mass 6.0 μg ) moving in the neighboring space. Evaluate the potential energy of Q2 when it is 4.0 cm from Q1. (Note: Q1 is held fixed in its place. ) k = 9.00×109 N. m2/C2 7.1 J 3.4 J 5.5 J 6.2 J
Find the ratio of speeds of an electron and a negative hydrogen ion (one having an extra electron) accelerated through the same voltage, assuming non-relativistic final speeds. Take the mass of the hydrogen ion to be 1.67×10-27 kg. Mass of an electron = 9.11×10-31 kg 42.8 50.5 75.0 30.5
An evacuated tube uses an accelerating voltage of 40 kV to accelerate electrons to hit a copper plate and produce X-rays. Nonrelativistically, what would be the maximum speed of these electrons? Mass of an electron = 9.11×10-31 kg Negative Charge of an electron = 1.6×10-19 C 2.00×10^8 m/s 2.28×10^8 m/s 3.38×10^8 m/s 1.19×10^8 m/s
Find the maximum potential difference between two parallel conducting plates separated by 0.500 cm of air, given the maximum sustainable electric field strength in air to be 3×106 V/m. 30 kV 10 kV 15 kV 20 kV
A 0.500-cm-diameter plastic sphere, used in a static electricity demonstration, has a uniformly distributed 40.0-pC charge on its surface. What is the potential near its surface? k = 9.00×109 N.m2/C2 110 V 120 V 144 V 150 V
How far from a 1.00-μC point charge is the potential 100 V? k = 9.00×109 N.m2 /C2 100.0 m 75.0 m 80.0 m 90.0 m
Two parallel plates 10 cm on a side are given equal and opposite charges of magnitude 5.0×10-9 C. The plates are 1.5 mm apart. What is the potential difference between the plates? 90 V 80 V 75 V 85 V
What is the direction and magnitude of an electric field that supports the weight of a free electron near the surface of Earth? Mass of an electron = 9.11×10-31 kg Negative Charge of an electron = 1.6×10-19 C 5.58×10^-11 N/C 2.55×10^-11 N/C 6.66×10^-11 N/C 7.25×10^-11 N/C
Calculate the work done on a 1500-kg elevator car by its cable to lift it 40.0 m at constant speed, assuming friction averages 100 N. 650 kJ 700 kJ 593 kJ 450 kJ