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The lopsided barbell Where would you have to hold this barbell to balance it on one finger?

The lopsided barbell Where would you have to hold this barbell to balance it on one finger?. 1.5 kg. 1.0 kg. 0.75 m. I earth = 0.345 M earth R earth 2. I moon = 0.392 M moon R moon 2. h i =37 cm. diameter=21 cm. QUIZ (turn this in)

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The lopsided barbell Where would you have to hold this barbell to balance it on one finger?

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  1. The lopsided barbell Where would you have to hold this barbell to balance it on one finger? 1.5 kg 1.0 kg 0.75 m

  2. Iearth = 0.345 MearthRearth2 Imoon = 0.392 MmoonRmoon2

  3. hi=37 cm diameter=21 cm QUIZ (turn this in) A 25 g ball bearing goes around a loop. If the ball bearing is released from rest and there is negligible friction with the track, 1. What is the ball’s speed at the bottom of the track? 2. What is its speed at the top of the loop? 3. In reality there’s friction. The ball is measured to have v=1.8 m/s when it leaves the loop. How much energy is converted to thermal energy? 4. If it takes 0.9 sec from release to exit, what is the average power dissipated as heat by the track and ball?

  4. An enormous letter ‘H’ falls down. The letter was 9 m x 9 m with a uniform mass of 63000 kg. Approximate the ‘H’ as 7 blocks of equal dimensions as shown below. * What is the moment of inertia of this structure? * How fast will the top of the ‘H’ be moving when it hits the horizontal ground? 9 m 9 m

  5. Right hand rule, for cross products • Version 1: • Point the fingers on your right hand in direction of first vector. • Move the fingers to point in the direction of second vector. • Your right thumb (sticking straight out) will point in the direction of the answer. • Version 2: • Point your right index finger in direction of first vector. • Point your right middle finger in the direction of second vector. • Your right thumb (sticking straight out) will point in the direction of the answer.

  6. Three forces are applied to a door, as seen below. * Which force creates the largest torque? * In each case, which direction does  point? F1=15 N F2=15 N 45o door hinge F3=10 N

  7. Two 30 kg kids are standing on either end of a 50 kg, 2 m long beam with a pivot 0.4 m from one end. What’s the net torque on the beam?

  8. QUIZ: TURN THIS IN A 4.0 m long 500 kg steel beam extends horizontally from the point where it has been bolted to the framework of a new building under construction. A 70 kg construction worker stands at the far end of the beam. What is the magnitude of the torque about the point where the beam is bolted into place?

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