In an experiment to measure the quantum yield of a photochemical reaction, the absorbing substance was exposed to 490nm light from a 100w source for 45 min. the intensity of the transmitted light was 40% of the intensity of the incident light. as a result of irradiation, 0.344 mol of the absorbing substance decomposed. determine the quantum yield. (hint (1) calculate the total energy delivered to the source, (2) calculate the energy delivered by 490nm radiation per photon, (3) then calculate the number of photons, (4) then calculate the number of photons absorbed in mol and finally (5) you can calculate the quantum yield. the quantum yield is:
a) .89
b) .67
c) .52
d) .42

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation:

where is the circuit diagram ?

a=d/t

a="triangle"v/t

explanation:

a = acceleration

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards