Category: General Physics
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Maximum Possible Acceleration
In the soapbox Derby, young participants build non-motorized cars with very low friction wheels. Cars race by rolling down a hill. The track at Akron’s Derby Downs, where the national championship is held, begins with 55-ft long section tilted 13° below horizontal. a) What is the maximum possible acceleration of a car moving down this…
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Time for Ball to Hit Floor
A ball with a horizontal speed of 1.25 m/s rolls off a bench 1.00 m above the floor. How long will it take the ball to hit the floor? The ball falls from 1 meter above the floor. s = 1/2 g t2 g = 9.81 (acceleration of gravity ) t2 = 2s/g = 2.00/9.81 = 0.2…
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Frequency and Period
A typical hard disk in a computer spins at 7200 rpm. What is the frequency in rev/s? 1 min = 60 seconds 7200 / 60 = 120 rev/s What is the period in seconds? period = 1/7200 = 0.000138 minute = 0.0083 second = 8.3 x 10-3
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Radius and Speed with Hypothetical Modicfications
A particle rotates in a circle with centripetal acceleration a= 22 m/s 2. a) What is a If the radius is doubled without changing the particle’s speed? a = v2/r if radius is doubled, a = v2/2r or v2 x 1/2 22/2 : By looking at the equation, it should be halved since you are basically multiplying it by 1/2…
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Position vs. Time Graph
The position graph of the figure represents the motion of a ball being rolled back and forth by two children. At what positions are the two children sitting? x (m) denotes the position so you would have to look at the y axis. From the diagram you can see the answer is : +…
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Displacement
A car travels along a straight east-west road. A coordinate system is established on the road, with x increasing to the east. The car ends up 12 mi west of the intersection with Mulberry Road. First and foremost, we need to know the displacement equation. If its displacement was -27 mi , how far from…
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What is the Velocity?
A dog trots from -19 m to 7.0 m in 11 s. What is its velocity? Given variables: x1= -19 m x2= 7 m t = 11 s The equation for velocity is x2 – x1 / t 7 – (-19) / 11 7 + 19 = 26 26/ 11= 2.4 m/s
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What is the Position Relative to the Origin?
The figure below shows Sue somewhere between her home and the cinema. What is Sue’s position x if her home is the origin? Keep in mind, left is negative and right is positive. x = 2 What is Sue’s position x if the cinemea is the origin? x = -3
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What is the speed?
A security guard walks 110 m in one trip around the perimeter of the building. It takes him 260 s make this trip. What is his speed? The guard walked 110 meters in 260 seconds. To find the speed in m/s you have to divide the total distance by the total time. speed = 110m /…