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PH 201 Section 102 Name Test 1 01 Section 102 october October 3, 2006 Probbem Some uwal Infoenation all work! Total Universal Gravitational Constant G-6AT × 10-11 Short Questions (Total of 40 points) at time t-. 38 seconds. At tine tinn t-7.4 seconds, the particle guestiou 1 (5 pointa) A 3.0 kg particle in constraianl to tneoe along the X axis 1t iw bocsed m x 20 localed st x-53 m. Carlse the average velocity of the particle over this time interval. Qusstion 2 (5 points) Write Newtom'w first law of motion sa explsin whai i ssns 3 (10 points) A particle travelh along the X xis Its ponition Tunction time x(t)7t + 24t3 +3t, where all quantitis are in sppropriate Sl wnila Caletíladn th" vinity and celeration as function of time for this particle. tion 4 (10 pointa) A motor boat travels in a straight path on a caln lake with a speed of 7.A m/s Suddenly the motor stops and the boat starts to slow at rate of 090 m/a. Determine tin datance it takes for the bost to come to rest. Seore Qustion 5 (10 points) A truck traveling on a flat section of ruad turns aloeg a curve of naudius 63.0 m with Galralie the magaitade and direction of the acceleration, if any, of the truck il m
Explanation / Answer
1) Vavg = (x2-x1)/(t2-t1)
= (-5.3 - 2)/(7.4 - 0.3)
= -1.03 m/s
2) Newton's first law of motion :
Every body coninues in a state of rest or uniform motion unless a net force acted upon it.
mass is a measure of inertia.
3)
v = dx/dt
= 28*t^3 + 72*t^2 + 3
a = dv/dt
= 84*t^2 + 144*t
4) use kinematic equation
v^2 - u^2 = 2*a*s
s = (v^2 - u^2)/(2*a)
= (0^2 - 7.4^2)/(2*(-0.9))
= 30.4 m
