3. Suppose you're a detective working on a burglery case. Here's what you already know (and...

 

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3. Suppose you're a detective working on a burglery case. Here's what you already know (and refer also to the diagram): Sometime last night, robbers broke into a river- side bar and stole money. Night-surveillance cameras along the river banks show them stealing a boat as their getaway vehicle, crossing the river lo try to fool the police. The video recondings indicate that the robbers took 1:04 (I min, 4 s) to travel across the river from point A to point B, but that they aligned the boat always parallel to line segment AX. Before being stolen, the boat had been moored at point A. It was equipped only with a motor that nuns at just one speed; and tests indicate that the motor will propel the boat through water at a steady 2.61 m/s (relative to the water 38.7 thighway bridge) (river) current (har) The riverbanks are both straight and parallel in this area. The robbers abandoned the boat at point B, at the bae a straight highway bridge that crosses the river at a 38.7" angle, as shown. The robbers had placed a getaway car a point B and had evidently driven back over the bridge: According to a radar gun positioned on the highway,a lone vehicle was recorded at this time of night, going past point C at a high speed (54.7 m/s). The known straight-line distances: = 309 m dr = 256 m a. The radar gun that was focused on point C was not equipped with a night camera, so you don't know the make or model of the high-speed car. To try to narrow this down, first you'd like to get a senie of the car's engine size: Assuming that it accelerated from rest at a steady rate all the way across the highway bridge from point B to point C, what was that acceleration magnitude? b. Assuming that the boat moved at a constant velocity during the getaway crossing, what was that velocity, a measured with respect to the shore? c. In case the robbers accidentally dropped anything overboard, you'd like to estimate how far to extend a searchi for clues downstream. To begin your estimation: Assuming the river current was uniform and steady for the entire crossing (and again, assuming the boat moved at constant velocity)-how fast was the river current? (Save thix part for last; we will cover relative velocities in Class 7.) Remember: Diagnose the situation and then describe your solution-do no algebra or number crunching Name all known values! 3. Suppose you're a detective working on a burglery case. Here's what you already know (and refer also to the diagram): Sometime last night, robbers broke into a river- side bar and stole money. Night-surveillance cameras along the river banks show them stealing a boat as their getaway vehicle, crossing the river lo try to fool the police. The video recondings indicate that the robbers took 1:04 (I min, 4 s) to travel across the river from point A to point B, but that they aligned the boat always parallel to line segment AX. Before being stolen, the boat had been moored at point A. It was equipped only with a motor that nuns at just one speed; and tests indicate that the motor will propel the boat through water at a steady 2.61 m/s (relative to the water 38.7 thighway bridge) (river) current (har) The riverbanks are both straight and parallel in this area. The robbers abandoned the boat at point B, at the bae a straight highway bridge that crosses the river at a 38.7" angle, as shown. The robbers had placed a getaway car a point B and had evidently driven back over the bridge: According to a radar gun positioned on the highway,a lone vehicle was recorded at this time of night, going past point C at a high speed (54.7 m/s). The known straight-line distances: = 309 m dr = 256 m a. The radar gun that was focused on point C was not equipped with a night camera, so you don't know the make or model of the high-speed car. To try to narrow this down, first you'd like to get a senie of the car's engine size: Assuming that it accelerated from rest at a steady rate all the way across the highway bridge from point B to point C, what was that acceleration magnitude? b. Assuming that the boat moved at a constant velocity during the getaway crossing, what was that velocity, a measured with respect to the shore? c. In case the robbers accidentally dropped anything overboard, you'd like to estimate how far to extend a searchi for clues downstream. To begin your estimation: Assuming the river current was uniform and steady for the entire crossing (and again, assuming the boat moved at constant velocity)-how fast was the river current? (Save thix part for last; we will cover relative velocities in Class 7.) Remember: Diagnose the situation and then describe your solution-do no algebra or number crunching Name all known values!