Author Archives: Anonymous
A 40-kg crate is being lowered with a downward acceleration…
A 40-kg crate is being lowered with a downward acceleration is 2.0 m/s2 by means of a rope. (a) What is the magnitude of the force exerted by the rope on the crate? (b) What would be the magnitude of the force exerted by the rope if the crate were being raised with an acceleration of 2.0 m/s2?
Read Details1) The label on a certain small appliance states that the ap…
1) The label on a certain small appliance states that the appliance carries a current of 5.0 A when connected to a source of 120 V. What is the resistance of the appliance? (5 points) 2) Consider the circuit shown below. Calculate the equivalent (total) resistance of the circuit. (5 points) 3) A battery with a 18 V emf and an internal resistance of 0.050 Ohms provides a current of 25 A to a circuit. Calculate the terminal voltage of the battery. (5 points) 4) A series RLC AC circuit has resistance R = 650 Ohms, inductance L = 0.900 H, capacitance C = 7.50 micro Farad, frequency f = 60.0 Hz, and Vmax = 150 V. Find the total impedance of the circuit.(5 points)
Read Details1) Suppose an astronaut travels so fast that γ = 35. She tra…
1) Suppose an astronaut travels so fast that γ = 35. She travels from the Earth to a star 4.8 light years (ly) away as measured by an Earth-bound observer. How far apart are the Earth and the star as measured by the astronaut? (5 points) 2) How much energy is emitted during the transition of an electron that makes the fourth line of Balmer series? (5 points) 3) What is the wavelength of the 5th line in the Lyman series? (5 points) 4) Suppose a spaceship heading straight towards the Earth at 0.850 c can shoot a canister at 0.550 c relative to the ship. What is the velocity of the canister relative to the Earth, if it is shot directly at the Earth? (5 points)
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