Questão 1
Questão
The corners of a square lie on a disk of radius r = 51 cm. What is the area of the square, expressed in square feet?
Responda
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2.8 ft^2
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4.4 ft^2
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5.6 ft^2
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8.8 ft^2
Questão 2
Questão
A person’s blood pressure is measured to be 120 ± 2mm Hg. What is its percent uncertainty?
Questão 3
Questão
A woodpecker’s brain is specially protected from large decelerations by tendon-like attachments inside the skull. While pecking on a tree, the woodpecker’s head comes to a stop from an initial velocity of 0.600 m/s in a distance of only 2.00 mm. Find the acceleration in m/s^2 and in multiples of g (g = 9.80 m/s^2).
Responda
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-90.0 m/s^2, -9.18 g
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90.0 m/s^2, 4.00 g
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-45.0 m/s^2, -9.18 g
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-33.0 m/s^2, -10 g
Questão 4
Questão
A swimmer bounces straight up from a diving board and falls feet first into a pool. She starts with a velocity of 4.00 m/s, and her takeoff point is 1.80m above the pool. What is her highest point above the board?
Responda
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1.40 m
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3.21 m
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0.204 m
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0.816 m
Questão 5
Questão
Find the following for path C. (a) The distance traveled. (b) The magnitude of the displacement from start to finish.
Responda
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13 m, 6 m
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8 m, 12 m
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12 m, 8m
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14 m, 7 m
Questão 6
Questão
Consider the quantities x = 10 t and y = 5.0 t^2, which are dependent on t. The value of z = y – x at t = 4.0 ± 0.1 is equal to
Responda
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40.0 ± 0.5
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40 ± 5
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40 ± 1
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40 ± 2
Questão 7
Questão
A ball is kicked with an initial velocity of 16 m/s in the horizontal direction and 12 m/s in the vertical direction. At what speed does the ball hit the ground?
Responda
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15 m/s
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20 m/s
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13 m/s
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10 m/s
Questão 8
Questão
A rugby player passes the ball 7.00 m across the field, where it is caught at the same height as it left his hand. At what angle was the ball thrown if its initial speed was 12.0 m/s, assuming that the smaller of the two possible angles was used?
Responda
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15 degrees
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28.4 degrees
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14.2 degrees
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36.6 degrees
Questão 9
Questão
A passenger train is traveling at 108 km/h when the engineer sights a freight train whose caboose is 200 m ahead on the same track. The velocity of the freight train is 43.2 km/h in the same direction. The engineer immediately applies the brakes, which causes the passenger train to slow down at a uniform rate of 0.800 m/s^2, while the other train continues at the same speed. The two trains collide after:
Responda
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20.0 s
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7.40 s
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54.2 s
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67.6 s
Questão 10
Questão
Near the end of a marathon race, the first two runners are separated by a distance of 45.0 m. The front runner has a velocity of 3.50 m/s, and the second a velocity of 4.20 m/s. (a) What is the velocity of the second runner relative to the first?
Responda
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5.00 m/s
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0.170 m/s
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0.700 m/s
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2.00 m/s
Questão 11
Questão
A firefighting helicopter takes 1800 kg load of water from a river and accelerates upward at 0.87 m/s^2. If the mass of the helicopter is 2700 kg, the main motor exerts a lift force equal to
Questão 12
Questão
Suppose a 60.0 kg gymnast climbs a rope. What is the tension in the rope if he accelerates upward at a rate of 1.50 m/s^2?
Questão 13
Questão
What force would you have to exert perpendicular to the center of the rope to produce a force of 12,000 N on the car if the angle is 2.00 degrees?
Responda
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568 N
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419 N
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1.20 x 10^4 N
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838 N
Questão 14
Questão
A nurse pushes a cart by exerting a force on the handle at a downward angle 35.0 degrees below the horizontal. The loaded cart has a mass of 28.0 kg, and the force of friction is 60.0 N. What force must the nurse exert to move at a constant velocity?
Responda
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73.2 N
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105 N
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82.5 N
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36.6 N
Questão 15
Questão
A 4.00 kg block slides on the surface of an inclined table, which makes an angle of 15.0 degrees with the horizontal. The block is connected through cords over two pulleys to a 7.26 kg bowling ball on the upper side of the table, and a 3.00 kg ball on the lower side. The pulleys are massless and frictionless, while the coefficient of kinetic friction between the block and the table's surface is 0.470. Determine the direction of motion and acceleration of the system.
Responda
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2.00 m/s
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0.97 m/s
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3.00 m/s
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1.15 m/s
Questão 16
Questão
A rod consists of a 30.0cm long glass section glued to a 45.0cm brass section. The rod has a uniform cross-sectional diameter of 1.00cm. Calculate the total compression of the rod (in millimetres) when it is under a compressive force of magnitude F = 6,600N. The Young's modulus for glass and brass is 70 x 10^9 N/m^2 and 90 x 10^9 N/m^2 respectively.
Responda
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1.00 mm
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0.06 mm
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0.78 mm
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0.45 mm
Questão 17
Questão
Calculate the ideal speed to take a 100 m radius curve banked at 15.0 degrees.
Responda
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58.3 km/h
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16.2 km/h
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75.0 km/h
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26.3 km/h
Questão 18
Questão
At takeoff, a commercial jet has a 60.0 m/s speed. Its tires have a diameter of 0.850 m. With what force must a determined 1.00×10^−15 kg bacterium cling to the rim?
Responda
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9.80 x 10^-15 N
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1.40 x 10^-15 N
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8.47 x 10^-12 N
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6.90 x 10^-14 N
Questão 19
Questão
A spy satellite completes six revolutions every day in a circular orbit. Determine the altitude of the satellite above Earth's surface.
Responda
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1.28 x 10^7 m
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4.57 x 10^10 m
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6.67 x 10^11 m
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6.42 x 10^6 m
Questão 20
Questão
A 5.00 x 10^5 kg subway train is brought to a stop from a speed of 0.500 m/s in 0.400 m by a large spring bumper at the end of its track. What is the force constant k of the spring?
Responda
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6.25 x 10^5 N/m
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7.81 x 10^5 N/m
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5.67 x 10^5 N/m
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1.56 x 10^6 N/m
Questão 21
Questão
A box slides on a smooth (frictionless) horizontal surface, 1.5m above the floor, at a speed of 2.0 m/s. The box then slides down a ramp that makes an angle of 36 degrees with the horizontal and has a coefficient of kinetic friction equal to 0.43. After reaching the end of the ramp, the box continues to slide horizontally on the smooth floor. Use the law of conservation of energy to calculate the final speed (v) of the box.
Responda
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5.23 m/s
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4.00 m/s
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7.34 m/2
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2.00 m/s
Questão 22
Questão
A 14,000 kg tractor traveling north at 21 km/h turns west and travels at 26 km/h. Calculate the change in the tractor's linear momentum (magnitude and direction).
Responda
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1.94 x 10^4 kg x m/s, 38.9 degrees
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8.17 x 10^4 kg x m/s, 45.0 degrees
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1.27 x 10^5 kg x m/s, 34.7 degrees
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1.30 x 10^5 kg x m/s, 38.9 degrees
Questão 23
Questão
What is the velocity of a 900 kg car initially moving at 30.0 m/s, just after it hits a 150-kg deer initially running at 12.0 m/s in the same direction? Assume the deer remains on the car.
Responda
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24 m/s
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30 m/s
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23.8 m/s
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27.4 m/s
Questão 24
Questão
To get up on the roof, a person (mass 70.0 kg) places a 6.00-m aluminum ladder (mass 10.0 kg) against the house on a concrete pad with the base of the ladder 2.00 m from the house. The ladder rests against a plastic rain gutter, which we can assume to be frictionless. The center of mass of the ladder is 2 m from the bottom. The person is standing 3 m from the bottom. What are the magnitudes of the forces on the ladder at the top and bottom?
Responda
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133 N, 795 N
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200 N, 850 N
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795 N, 133 N
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408 N, 650 N
Questão 25
Questão
Calculate the direction and magnitude of the force supplied by the upper vertebrae FV to hold the head stationary, assuming that this force acts along a line through the center of mass as do the weight and muscle force.
Responda
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53.2 N, 80.5 degrees
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96.8 N, 58.7 degrees
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58.7 N, 96.8 degrees
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33 N, 25 degrees
Questão 26
Questão
A square plate has a side length of 1.20 m. A 24.0 N⋅m torque is applied about an axis perpendicular to the plate through its center. If it experiences an angular acceleration of 6.25 rad/s^2, calculate the mass of the plate.
Responda
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2.67 kg
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10.7 kg
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16 kg
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19.2 kg
Questão 27
Questão
What is the final velocity of a hoop that rolls without slipping down a 5.00 m-high hill, starting from rest?
Responda
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7.00 m/s
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6.50 m/s
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4.95 m/s
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8.00 m/s