A deep-sea robotic probe of mass m m\,m is lowered into the ocean by a vertical cable. The probe descends with a constant downward acceleration aaa. The seawater exerts an upward buoyant force B B\,B and a resistive drag force D D\,D on the probe.
If g g\,g is the acceleration due to gravity, what is the tension T T\,T in the cable?
T=m(g+a)−(B+D)T = m(g + a) - (B + D)T=m(g+a)−(B+D)
T=m(g−a)−(B+D)T = m(g - a) - (B + D)T=m(g−a)−(B+D)
T=m(g−a)+B+DT = m(g - a) + B + DT=m(g−a)+B+D
T=m(g+a)+B+DT = m(g + a) + B + DT=m(g+a)+B+D
84 exam-style questions on AQA A Level Physics Force, energy and momentum, covering Scalars and vectors, Moments, Motion along a straight line, Projectile motion, Newton's laws of motion, Momentum, Work, energy and power, and Conservation of energy. Each one has a worked solution and a mark scheme showing where the marks go.