Recent content by crosbykins

Homework Statement a) What is the energy of the neutrino, if a phosphorus-32 atom (31.97390 u) beta-decays into a sulphur-32 atom (31.97207 u), and the kinetic energy of the accompanying electron is 0.90 MeV? (answer: 0.25 MeV) b) A boron-12 atom (12.01435 u) beta-decays into a...

Homework Statement Would 449-nm blue light eject electrons from silver metal with a work function of 4.74 eV? Homework Equations E = hc/lamba The Attempt at a Solution E = [(6.63*10^-34 J*s)(3.00*10^8 m/s)]/(4.49*10^-7 m) = 4.42*10^-19 J 4.42J/1.60*10^-19 J/eV = 2.77 eV...

Homework Statement A distant star has been measured as moving at a speed of 0.8c away from Earth. If a planet of this star sends radio signals to Earth once every second (according to their time scale), how often would we receive them (according to out time scale)? Homework Equations...

Homework Statement A piece of paper of thickness 15 * 10^-6 m is used to create an air wedge between 2 glass slides that are 7.25 cm long. If the wavelength of the light being used is 595 nm, how many interference fringes are counted across the entire pattern? Homework Equations delta...

Homework Statement An electron is accelerated horizontally from rest in a television picture tube by a potential difference of 10,000 V. It then passes between two horizontal plates 5.0 cm long and 1.0 cm apart which have a potential difference of 200 V. At what angle θ will the electron be...

Homework Statement An electron is accelerated horizontally from rest in a television picture tube by a potential difference of 10,000 V. It then passes between two horizontal plates 5.0 cm long and 1.0 cm apart which have a potential difference of 200 V. At what angle θ will the electron...

Homework Statement How much work is done against gravity to fire a 7.2*10^2 kg weather monitor 120km into the air. Homework Equations Mass Earth = 5.98*10^24kg radius of Earth = 6.38 * 10^6 m Eg = -GMm/r delta Eg = Eg 2 - Eg 1 The Attempt at a Solution Eg1= -[(6.67*10^...

the question calls it a synchronous satellite...is this the same thing

ok well then i don't mean geocentric i just mean that it has the same orbit period as the Earth

because in my textbook it gives 3.16*10^7 s as the period of revolution of orbit for earth, so since the satellite is geocentric its period is the same

Homework Statement What is the height of a geostationary satellite measured from the Earth's centre? Homework Equations r^3/T^2 = GM/4pi^2 T of Earth = 3.16 * 10^7 s The Attempt at a Solution GM/4p2 = r3/T2 3root[T2 * GM/4p2 ] = r 3root[(3.16*107 s)2 *...

Homework Statement A 0.020 kg cart is held between two identical, stretched springs. A force of 2.0 N is employed to hold the cart in a position 0.10m from equilibrium. The cart is then released and allowed to vibrate from the 0.10 position. a) What is the force constant for the...

Thank you so much for your help! :smile:

1. A 0.20g flea sits at a distance of 5.0cm from the centre of a rotating record. a) If the record rotates at 77rpm, what is the centripetal force. b) For the flea to remain at this spot, what must be its frictional force? 2. A pilot of mass 60.0kg is flying her plane in a vertically...

i meant Fnormal is 0, so the only force acting on the pilot when she is at the bottom is gravity