Estimate the radiation pressure due to a bulb that emits 25 W of EM radiation at a distance of 9.5 cm from the center of the bulb. Assume that light is completely absorbed. Express your answer to two significant figures and include the appropriate units.

Given Information:  

Power of bulb = w = 25 W atts

distance = d = 9.5 cm = 0.095 m

Required Information:  

Radiation Pressure = ?

Radiation Pressure =7.34x10⁻⁷ N/m²

Explanation:

We know that radiation pressure is given by

P = I/c

Where I is the intensity of radiation and is given by

I = w/4πd²

Where w is the power of the bulb in watts and d is the distance from the center of the bulb.

So the radiation pressure becomes

P = w/c4πd²

Where c = 3x10⁸ m/s is the speed of light

P = 25/(3x10⁸*4*π*0.095²)

P = 7.34x10⁻⁷ N/m²

Therefore, the radiation pressure due to a 25 W bulb at a distance of 9.5 cm from the center of the bulb is 7.34x10⁻⁷ N/m²

russian is not my first language, so i'm afraid i can't write out an answer in russian, but hopefully you can find a way to do so. here's my best translation of the problem: you're given a plot of a particle's position in one-dimensional space over time, and you're asked to find either the total distance traveled by the particle after 6 seconds had elapsed, or the total displacement of the particle after 6 seconds.

if you want the total distance traveled, you would first need to determine the particle's velocity as a function of time, then integrate that over the 6-second interval. we know the position function is quadratic with roots at 0 and 6, so we have

where is unknown. because the position is parabolic, there is symmetry about the midpoint at , and we know that

so that the position function is

which means the velocity is

then the total distance traveled is

so the total distance traveled is 20 m.

on the other hand, if you want to find displacement: the particle starts at and ends at , so its displacement is 0.