Category: General Physics
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What is the Speed?
The blade on a table saw spins at 3650 rpm. Its diameter is 25.0 cm.? a) What is the speed of a tooth on the edge of the blade in m/s? Angular speed w = 3650 rpm = 3650 * 2*pi rad / 60 s = 382.22 rad / s Diameter d = 25 cm radius r = d / 2…
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Centripetal Acceleration
To withstand “g-forces” of up to 10 g’s, caused by suddenly pulling out of a steep dive, fighter jet pilots train on a “human centrifuge.” 10 g’s is an acceleration of 98 m/s2 If the length of the centrifuge arm is 15.0 m, at what speed is the rider moving when she experiences 10…
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What is the magnitude of the net force?
A 1300 kg car drives around a flat 180 m-diameter circular track at 22 m/s. What is the magnitude of the net force on the car? Fc= m * ac = m * v2/r =1300 * (22)2/(180/2) = 6991 =7000 N
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What is the Centripetal Acceleration and Magnitude?
A fast pitch softball player does a “windmill” pitch, moving her hand through a vertical circular arc to pitch a ball at 68 mph. The 0.20 kg ball is 55 cm from the pivot point at her shoulder. 1) Just before the ball leaves her hand, what is its centripetal acceleration? ( 68 mph…
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What is the acceleration from the axis of rotation?
A typical laboratory centrifuge rotates at 4000 rpm. Test tubes have to be placed into a centrifuge very carefully because of the very large accelerations. 1) What is the acceleration at the end of a test tube that is 10 cm from the axis of rotation? Ac = v2/r The radius is 10cm or .10m The…
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What is its Orbital Period?
An earth satellite moves in a circular orbit at a speed of 7000m/s? What is its orbital period? r = GM/v2 r: distance of the satellite from the center of Earth in m M is the mass of Earth: 5.974 x 1024 v is the orbital speed: 7000 m/s r = 6.674x 10-11 x 5.974 x 1024/70002 r = 8137445…
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Gravitational Force
What is the gravitational force of the sun on the earth? What is the gravitational force of the moon on the earth? The moon’s force is what percent of the sun’s force? F = G m₁m₂/r² G = 6.67 x 10-11m³/kgs² What is the gravitational force of the sun on the earth? F = 6.67e-11…
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What is the Angular Displacement and Velocity?
What is the angular displacement of the wheel between t=5 s and t=15 s? What is the angular velocity of the wheel at 15 s? Judging from the graph, t = 5 s is 100 rad t = 15 s is 125 rad Angular Displacement = 125 – 100 ( vector quantity) Considering, Clockwise 50 and…
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Magnitude and Direction of Tension
The three ropes in the figure are tied to a small, very lightring. Two of these ropes are anchored to walls at right angles withthe tensions shown in the figure. What is the magnitude of the tension T3 in the third rope? T3 = √(T12 +T22) = 94.3 n T3 = 94 N What is the direction of…
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What is the Tension?
A cable is used to raise a 21 kg urn from an underwater archeological site. There is a 22 N drag force from the water as the urn is raised at a constant speed. What is the tension of the cable? Newton’s Second Law: the sum of the forces on an object in a given direction…