The apollo program (not the lunar missions with astronauts) being conducted at the apache point observatory uses a 3.5-m telescope to direct lasers at retro-reflectors left on the moon by the apollo astronauts. if the moon is 384,472 km away, approximately how long do the operators need to wait to see the laser light return to earth?

Ahonda civic travels in a straight line along a road. its distance x from a stop sign is given as a function of time t by the equation x(t)= î± t2â î² t3, where î± = 1.53 m/s2 and î² = 5.50ã10â2 m/s3 .

Assume you measured the mass of the cart to be (500 ± 1) g and the mass of the additional mass you put on the cart to be (500 ± 1) g as well. since the scale you are using in the lab cannot measure objects heavier than 600g you will have to sum up individual pieces and propagate the error. so what would be the mass and the standard error of the cart and the mass

Cyclotrons are widely used in nuclear medicine for producing short-lived radioactive isotopes. these cyclotrons typically accelerate h- (the hydride ion, which has one proton and two electrons) to an energy of 5 mev to 20 mev. this ion has a mass very close to that of a proton because the electron mass is negligible—about 1 2000 of the proton’s mass. a typical magnetic field in such cyclotrons is 1.9 t. (a) what is the speed of a 5.0-mev h-? (b) if the h- has energy 5.0 mev and b = 1.9 t, what is the radius of this ion’s circular orbit?