PhysicsBowl-2015真题

1.Which one of the following choices correctly represents a length of 3.00 mm?(A)3.00×10-6mB)3.00×10-3m(C3.00×10-2m①)3.00×103mE)3.00×106mB...milli represents 10-32.A box uniformly slides 7.50 m to rest across a flat surface in a time of 12.0 s.What was the initial speed ofthe box when it started its slide?(A)0.313®)0.625(C1.25m(D)2.50四(E)5.00四C...METHOD #1:Using constant acceleration kinematics.we have the average velocity computed as()=g=75=0.625 which1 leads to(m)=(,+y)→0.625=(+0)→6=125gMETHOD #2:One can graph velocity vs time for the box.Knowing that the area under the curve isthe change in position.we have A=bh.5(12.0)voo=1.253.Which one of the following quantities is not a vector quantity?(A)Average speed (B)Average velocity (C)Linear momentum (D)Acceleration (E)Average forceA...Vector quantities point...and speed is a scalar.4.A standing wave on a string is produced.Which one of the following choices best describes the location onthe string at which maximum constructive interference occurs?(A)node(B)antinode(C)harmonic(D)overtone(E)amplitudeB...Locations of complete constructive interference are known as antinodes on the standing wave.5.An object initially is moving upward while in free fall.Which one of the following choices best representsthe direction of the object's acceleration during its flight?Object moving upwardObject at peak of motionObject moving downward(A)UpwardZeroDownward(B)DownwardZeroDownward(C)UpwardDownwardDownward(D)DownwardZeroUpwardE)DownwardDownwardDownwardE...The gravitational force is always directed downward!!6.Acar travels at 20.0Which one of the following choices best represents the speed of thec inSIhrunits of()533四(B)45.0四(C20.0四D)8.9四E0.75号D.Converting uits..20me×1r×1m×16o0m=8.9"hr60 min 60s1mi7.An object moves clockwise with constant speed around the vertical circle shown.Which arrow bestindicates the direction of the object's instantaneous acceleration at the point labeled X?Acceleration at X(A)→(B)(C)←一D(E)There is no acceleration.A...Objects that move in uniform circular have a velocity direction change toward the center of thecircle being traced out