Cracking the SAT Physics Subject Test
moon would imply a smaller normal force by the table and hence a smaller frictional force. Less force would be needed on the moo ...
CHAPTER 4 DRILL A Since the force F is perpendicular to the displacement, the work it does is zero. B By the work–energy theore ...
Note: Wtotal = ∆K could also be used. E Apply conservation of mechanical energy (including the negative work done by Fr, the fo ...
Again, Wtotal = ∆K could also be used. E Because the rock has lost half of its gravitational potential energy, its kinetic ener ...
K is proportional to v^2 , if Kat halfway point is equal to Kat impact, then the rock’s speed at the halfway point is its speed ...
CHAPTER 5 DRILL C Use the equation Q = mc∆T. Q = (0.04 kg)(0.50 kJ/kg • °C)(50°C − 20°C)=0.6 kJ = 600 J D Phase changes obey ...
the ideal gas law, PV = nRT, tells us that P and T are proportional. Therefore, if T increases by a factor of 2, then so does P. ...
CHAPTER 6 DRILL C The magnitude of the object’s linear momentum is p = mv. If p = 6 kg · m/s and m = 2 kg, then v = 3 m/s. Ther ...
D First, apply conservation of linear momentum to calculate the speed of the combined object after the (perfectly inelastic) co ...
Therefore, the ratio of the kinetic energy after the collision to the kinetic energy before the collision is C Total linear mom ...
CHAPTER 7 DRILL C By combining the equation for centripetal acceleration, ac = v^2 /r, with v = rω, we find D The torque is τ ...
From the diagram, sinθ = 40 cm/L, so Lsinθ = 40 cm. That is, the ...
question gave the lever arm already. (The given 60° angle was irrelevant.) Thus, from τ = Fℓ, the torque is (0.40 m)(0.50 kg)(10 ...
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Note that the center of mass formula could also be used to find m 2 , though it would require algebra. Typically, the center of ...
Now, applying the equation for locating the center of mass (letting y = 0 denote the position of the center of mass of the top h ...
satellite, so. This gives , so the kinetic energy K of the satellite is inversely proportional to R. Therefore, if R increases b ...
B Kepler’s Third Law says that T^2 ∝ R^3 for a planet with a circular orbit of radius R. Since T ∝ , if R increases by a facto ...
a factor of A Since the centripetal force on each satellite is equal to the gravitational force it feels due to the earth, the ...
CHAPTER 8 DRILL D The acceleration of a simple harmonic oscillator is not constant, since the restoring force—and, consequently ...
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