Physics Rotational Mechanics Level: High School
Rotational Equilibrium
A rod is being used as a lever as shown . The fulcrum is 1.2 m from the load and 2.4 m from the applied force . If one load has a mass of 17.4 kg . What force must be applied to lift the load ?
Physics Rotational Mechanics Level: High School
Rotational Equilibrium
A house painter is standing on a uniform , horizontal platform that is held in equilibrium by two cables attached to supports on the roof . The painter has a mass of 77 kg and the mass of the platform is 20.5 kg. The distance from the left end of the platform to where the painter is standing is d = 2.0 m and the total length of the platform is 5.4 m .a) How large is the force exerted by the left-hand cable on the platform ?
b) How large is the force exerted by the right-hand cable ?
Physics Rotational Mechanics Level: High School
Rotational Kinetic Energy
A centrifuge has a rotational inertia of 5.4 x 10^3 kg m^2 . How much energy must be supplied to bring it from rest to 380 rad/s ?
Physics Rotational Mechanics Level: High School
Rotational Kinetic Energy
As a project your team is given the task of designing a spaceship of four different habitats . Each habitat is an enclosed sphere containing all necessary life support and laboratory facilities . The masses of these habitats are 10 x 105 kg , 20 x 105 kg , and 40 x 105 kg , and 40 x 105 kg . The entire station must spin so that the inhabitants will experience an artificial gravity . Your team has decided to arrange the habitats at corners of a square with 1.0 kg sides . The axis of rotation will be perpendicular to the plane of the square and through the center of mass . To help decide if this plan is practical ,you calculate how much energy would be necessary to set the space station spinning at 5.0 revolutions per minute . In your team’s design , the size of each habitat is small compared to the size of the space between the habitats and the structure that holds the habitats together is much less massive than any single habitat .
Physics Kinematics Level: High School
Resultant Velocity
A person has a mass of 80 kg. They go for a run with a constant speed of 3.5 m/s. When running against a constant resistive wind force a person needs to generate 50 W more than when they run with the same wind force pushing them forward . How strong is the wind force ? How much power does this person have to generate when running with the wind ?
Physics Alternating Current Level: High School
LC Oscillator
An LC circuit is built with a 20.0 mH inductor and an 7.70 microfarrad capacitor . The current has its maximum value of 0.600 A at t = 0 s. How long is it until the capacitor is fully charged ? and what is the value across the capacitor at that time ?
Physics Electromagnetic Induction Level: High School
An electrical generator contains a coil of 110 turns of wire , each forming a rectangular loop 55.7 cm by 35.3 cm . The coil is placed entirely in a uniform magnetic field with magnitude B = 3.92 T and initially perpendicular to the coil’s plane . What is in volts the maximum value of the emf produced when the loop is spun at 1310 rev/min about an axis perpendicular to the magnetic field ?
Physics Electromagnetic Induction Level: High School
A uniform magnetic field is perpendicular to the plane of a circular loop of diameter 13 cm formed from wire of diameter 1.9 mm and resistivity of 1.47 x 10^-8 ohm-m . At what rate must the magnitude of the magnetic field change to induce a 9.2 A current in the loop ?
Physics Electromagnetic Induction Level: High School
A small loop of area A = 6.8 mm^2 is inside a long solenoid that has n = 748 turns/cm and carries a sinusodally varying current I of amplitude 2.97 A and angular frequency 336 rad/s . The central axis of the loop and solenoid coincide . What is in millivolts the amplitude of the emf induced in the loop ?
Physics Properties Of Matter Level: High School
Archimedes Principle
A hemispherical shaped bowl is floating on the surface water; the mass of the bowl is 0.6 kg . Water is poured into the bowl ; when 4.3 kg of water has been added , the bowl just sinks . What is the outer radius of the bowl .
Physics Force & Laws Of Motion Level: High School
Conservation of Momentum
Two government agents (FBI agents Mulder and Scully) need your physics expertise to determine why an alien spaceship exploded . The wreckage of the spaceship is in three large pieces around a western Nebraska town . The center of mass of one piece (mass = 300 kg ) of the spaceship landed 6.0 km due north of the center of town . Another piece (mass = 1000 kg) of the spaceship landed 6.0 km due north of the center of town . Another piece (mass = 1000 kg) landed 1.6 km to the southeast (36 degrees south of east ) of the center of town . The last piece (mass = 400 kg) landed 4.0 km to the southwest (65 degrees south of west) of the center of town. There are no more pieces of the spaceship. The army, which was watching the spaceship on its radar, claims it was hovering motionless over the center of town when the spaceship spontaneously exploded and the pieces fell to the ground . Agents Mulder and Scully do not believe that the spaceship exploded on its own accord . They think a missile hit it . They ask you to determine whether the fragments found are consistent with the spaceship exploding spontaneously, if not, determine from what direction the missile came . (For simplicity, assume that the pieces of the spaceship after the explosion are moving horizontally,)
Physics Force & Laws Of Motion Level: High School
Conservation of Momentum
A certain nucleus at rest spontaneously disintegrates into three particles . Two of them are detected . One has mass 16.7 x 10^-27 kg and velocity 6 x 10^8 m/s in the x-direction, the second has a mass 8.35 x 10^-27 kg and velocity 8 x 10^6 m/s in the y-direction . a) The mass of the third particle is 11.7 x 10^-27 kg ,what is the velocity ? b) How much energy is converted into kinetic energy by the disintegration process ?
Physics Work,Power & Energy Level: High School
Conservation of Energy
A 1.5 kg block is attached to a spring with constant 2000 N/m . The spring is then stretched a distance of .3cm and the block is released from rest . The speed of the block is it passes through the equilibrium position with no friction is 11 m/s . What is the speed of the block as it passes through the equilibrium position if a constant frictional force of 2N , and what would the strength of the frictional force be it the block reached the equilibrium position the first time when zero velocity .
Physics Waves And Oscillations Level: High School
Energy of Simple Harmonic Motion
A simple harmonic oscillator has a total energy E . Determine the kinetic and potential energies when the displacement is half the amplitude , and for what value does the kinetic energy equal the potential energy ?
Physics Rotational Mechanics Level: High School
Centre of Mass
The figure shows (at “click here” ) , four point masses are placed as shown. The x-and y-coordinates of the center of mass are closest to :a) (2.2, 2.6)
b) (2.2, 2.7)
c) (2.3, 2.6)
d) (2.3, 2.7)
e) (2.3, 2.8)
