Mindblown: a blog about philosophy.

  • Identify all Forces

    A skier slides down a slope to the left at a constant speed.   Identify all forces acting on the object and draw a free-body diagram of the object.

  • 3 Point Motion Diagram

    Consider the three-point motion diagram in the figure. a) Is the object’s average speed between points 1 and 2 greater than, less than, or equal to its average speed between points 0 and 1? => Speed between points 1 and 2 is greater than speed between points 1 and 1. b) Find the average acceleration vector…

  • x & y Components

    a) What is the x-component of vector E of the figure in terms of the angle θ and the magnitude E? = -Ecosθ b) What is the y-component of vector E of the figure in terms of the angle θ and the magnitude E? = Esinθ c) For the same vector, what is the x-component in terms of the angle…

  • What is your Displacement?

    While visiting England, you decide to take a jog and find yourself in the neighborhood shown on the map shown in the figure. What is your displacement after running 2.5 km on Strawberry Fields,1.7 km on Penny Lane, and 5 km on Abbey Road?    First get the x & y y = 5 cos(40)…

  • 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…

  • 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…

  • What is the Takeoff and Horizontal Speed?

    A gray kangaroo can bound across a flat stretch of ground with each jump carrying it 9.0 m from the takeoff point.   If the kangaroo leaves the ground at a 20° angle, what is its takeoff speed ? R (range) = v02 sin2(θ) / g 9.0 m = v02 sin2(20) / 9.81 v0 = 11.7 m/s (takeoff…

  • 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

  • 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…

  • 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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