In the bohr model of the hydrogen atom the electron circulates around the nucleus in a path of radius 5.1❌10^-11 meter at a frequency of 6.8❌10^15 rev/sec. what value of magnetic field is set up at the center of the orbit?

In guinea pigs, assume black coat is completely dominant over white. to determine whether an unknown black guinea pig is pure or hybrid black, it should be crossed with bb, bb, bb

The energy released by a chemical reaction can be measured using a calorimeter. when barium hydroxide octahydrate crystals are reacted with dry ammonium chloride inside of a coffee cup calorimeter, the temperature of the 18.00 g of water in the calorimeter decreases from 30.0°c to 8.0°c. the equation for calculating energy absorbed or released by a reaction is: where q is the energy released or absorbed, m is the mass of water in the calorimeter, cp is the specific heat of water, and δt is the observed temperature change. if the specific heat of liquid water is 4.19 j/g·°c, how much energy was absorbed by the reaction?

Ahot-air balloonist, rising vertically with a constant speed of 5.00 m/s releases a sandbag at the instant the balloon is 40.0 m above the ground. after it is released, the sandbag encounters no appreciable air drag. compute the velocity of the sandbag at 0.250 s after its release.