You kick two balls from the top of a cliff. In one case, you kick the ball with a velocity of magnitude v at an angle of 6 > 0 from the horizontal, as shown. In the second case, you kick the ball with a velocity of the same magnitude v directed along the horizontal. Case 1 Case 2 V % _.. ag" _V> 9:00 In which case will the ball hit the ground in the shortest time from the moment you kick it? 0 Case 1 0 We can't say without knowing the height of the cliff. O The two balls will take the same time to get to the ground. 0 Case 2 Q We can't say without knowing the initial speed of the balls. A person of mass m is standing on a beam one third of its length from the beam's left end. The beam is meanwhile supported by two pylons, one at the left edge of the beam and one two-thirds of the its length from the left edge. (1/3) L m M (2/3) L What is the force exerted on the beam by the left pylon (shaded gray)? O (1/4m - 1/2M)g O (m - M)g O (m + M)g O (1/2m + 1/4M)g O ('/4m + 1/2M)g O (1/2m - 1/4M)gThree ideal gasses (A, B, and C) are composed of molecules of equal masses. The same number of moles of these three gasses are heated to different temperatures (TA, TB, and TC). The distrubution of molecular velocities in each case is shown above. Which of the following statements about these gasses are true? Select all that apply. A Number of Molecules Velocity D The average translational kinetic energy per molecule is the same for A, B, and C. D VRMS is largest for gas A. D TC > TB Cl VRMS is largest for gas C. D The average translational kinetic energy per molecule is largest in gas B. D TA 0.3. What will happen when the strip is heated by some amount, AT? 0 The strip will bend in the direction of metal A. O The strip will remain straight and get longer. 0 The strip will bend in the direction of metal B. O The strip will curve into an S shape. 0 The strip will remain completely unchanged. 0 The strip will twist like a helix. A submarine releases an air bubble with a volume of 1.5 cm3 from 200 m below the surface of the ocean. How large is the bubble when it reaches the surface? Assume the temperature changes from 22 C to 24 C between 200 m deep and the surface. (The density of water is 1000 kg/m3.) O 34 cm3 0 8cm3 0 51 cm3 0 1.5 cm3 0 21 cm3 0 31 cm3 0 16 cm3 From the point of view of conductive heat loss, which adaptations would be beneficial to animals living in extremely cold climates? O Thick skin O Thin skin O As small a surface area as possible given the volume of the animal O Lots of tissues, like muscle, with high thermal conductivity O As large a surface area as possible given the volume of the animal O Lots of tissues, like fat, with low thermal conductivitySuppose you have two insulated buckets containing the same amount of water at room temperature. You also happen to have two blocks of metal of the same mass, both at the same temperature, warmer than the water in the buckets. One block is made of aluminum and one is made of copper. You put the aluminum block into one bucket of water, and the copper block into the other. After waiting a while (long enough for the blocks and water to come to thermal equilibrium) you measure the temperature of the water in both buckets. Which is warmer? (Note that on an exam, we'd give you the details about aluminum and copper. In this case, see if you can nd the information you need yourself.) 0 The water in the bucket containing the aluminum block 0 The water in the bucket containing the copper block 0 The water in both buckets will be at the same temperature You place a 500 g block of an unknown subtance in an insulated container filled 2 kg of water. The block has an initial temperature of 50 degrees C. The water is initially at 20 degrees C. If the equilibrium temperature of the block and water is 25 degrees C, what is the specific heat of the block? The specific heat of water is 4186 J/kg K. O 2080 J/kg C O 750 J/kg C O 3349 J/kg C O 5545 J/kg C O 1189 J/kg C