A horizontal force of 5.0 N accelerates a 4.0 kg mass, from rest, at a rate of 0.50 m/s2 in the positive direction. What friction force acts on the mass?
A) +3.0 N
B) -3.0 N
C) +2.0 N
D) -2.0 N
E) -3.3 N
B
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Intensity: The rate of energy flow per unit area of a sinusoidal electromagnetic wave has an average value of 0.601 W/m2. What is the maximum value of the magnetic field in the wave? (c = 3.00 × 108 m/s, ?0 = 4? × 10-7 T ? m/A, ?0 = 8.85 × 10-12 C2/N ? m2)
A. 7.09 × 10-8 T B. 5.02 × 10-8 T C. 3.55 × 10-8 T D. 9.81 × 10-8 T E. 1.42 × 10-7 T
Pu is unstable. Which of the following nuclei might be a possible outcome of a single-step decay process from this nucleus?
A. 
B. 
C. 
D. 
E. 
A scuba diver has his lungs filled to half capacity (3 liters) when 10 m below the surface. If the diver holds his breath while quietly rising to the surface, what will the volume of the lungs be (in liters) at the surface? Assume the temperature is the same at all depths. (The density of water is 1.0 × 103 kg/m3.)
A. 5.9 B. 4.5 C. 6.4 D. 3.9 E. 3.1
A heavy stone of mass m is hung from the ceiling by a thin 8.25-g wire that is 65.0 cm long. When you gently pluck the upper end of the wire, a pulse travels down the wire and returns 7.84 ms later, having reflected off the lower end
The speed of sound in the room is 344 m/s, and the stone is heavy enough to prevent the lower end of the wire from moving. If the wire is vibrating in its second overtone, what is the frequency of the sound it will produce? A) 383 Hz B) 128 Hz C) 191 Hz D) 255 Hz E) 765 Hz