Experiment #1 Question: Does penicillin prevent infection? Hypothesis: If the medicine prevents infection, than the medicine will prevent the growth of bacteria that cause infection. Experiment: Leo placed two circles of paper in a Petri dish (something used for growing bacteria). One circle of paper was soaked in penicillin. The other had nothing on it. He poured a liquid filled with bacteria into the Petri dish. Both circles of paper were placed in the Petri dish about 3cm apart. At the end of the experiment, a circle with a radius of 2cm formed around the circle of paper soaked in penicillin. There were no bacteria growing in the 2cm circle. No change had occurred around the other circle of paper. The bacteria were growing well.

What is the relationship between the wavelength of a wave and it's energy?

Aroll in a paper machine is powered by a separately excited dc machine. operating point 1 (under load): the roll typically operates at 764 rpm and must provide 301 nm of torque to oppose the load of the paper. the armature voltage is 230v for this operating point operating point 2 (no load): when the load is removed the speed of the roll increases to 900 rpm (the field characteristics are unchanged) la ea dev m (a) calculate the maximum torque (units of nm) that the motor can supply with this applied voltage (b) calculate the value of the armature resistance, ra (in ohms) (c) at operating point 1 (loaded condition), the field current, i, and the total input power (armature field), are measured to be to be 10 a and 28,600 w respectively. use this information to calculate the value of the field resistance, rf (in ohms). (d) (d) at operating point 1 (loaded condition), calculate the motor efficiency. express your answer as a percent to at least 2 significant digits. (d) if the field voltage is reduced by 1/2, calculate the new stall torque (in nm) of the motor (f). if the field voltage is reduced by 1/2, calculate the new no-load speed (in rad/sec)

What is the momentum of a 2 kg object moving at 15 meters per second