Archimedes Principle, buoyancy

Hi. Can someone please walk me through the following problem? A 0.12 kg balloon is filled with helium (density = 0.179 kg/m^3). If the balloon is a sphere with a radius of 5.2 m, what is the maximum weight it can lift? Thank you!

Bernoulli's equation

Hi. Can someone please walk me through the following problem? The buildup of plaque on the walls of an artery may decrease its diameter from 1.1 cm to 0.75 cm. If the speed of blood flow was 15 cm/s before reaching the region of plaque buildup, find (a) the speed of blood flow and (b) the pressure drop within the plaque regio ...continues

Coulomb's Law

Hi. Can someone please walk me through the following problem? Given that q = +12 micro-C and d = 16 cm, (a) find the direction and magnitude of the net electrostatic force exerted on the point charge q2 in the figure below. (b) How would your answers to part (a) change if the distance d were tripled? (The figure shows a ci ...continues

Coulomb's Law

Hi. Can someone please walk me through the following problem? Two point charge lie on the x axis. A charge of +9.9 micro-Coulombs is at the origin, and a charge of -5.1 micro-C is at x = 10.0 cm. (A) At what position x would a third charge q3 be in equilibrium? (b) Does your answer to part (a) depend on whether q3 is positive ...continues

Electric Field

Hi. Can someone please walk me through the following problem? A +5.0 micro-Coulomb charge experiences a 0.20 N force in the positive y direction. If this charge is replaced with a -2.7 micro-C charge, what force will it experience? Thank you!

Fluids, Pressure

Conceptual question: What holds a suction cup in place? Thank you!

Fluids, conceptual question

Hi. Can someone please explain the following conceptual question to me? A helium-filled balloon is being transported in a car. As the car accelerates away from a stop light, in which direction does the balloon move relative to the car? Explain. Thank you!

Fluids, conceptual question

Hi. Can someone please explain the following conceptual question to me? Why is it more practical to use mercury in a barometer than water? Thank you!

fluids, blood pressure, conceptual Q

Hi. Can someone please explain the answer to the following conceptual question to me? When a person's blood pressure is taken, it is measured on the arm, at approximately the same level as the heart. How would the results differ if the measurement were to be made on the patient's leg? Would the pressure be greater, accordi ...continues

electrical potential energy

Hi. Can someone please tell me if I've gotten the right answer to this problem? A computer monitor accelerates electrons and directs them to the screen in order to create an image. If the accelerating plates are 1.2 cm apart, and have a potential difference of 25,000 V, what is the magnitude of the uniform electric field betw ...continues