Question

Constants In this example we will investigate the viability of using radiation pressure to propel a spacecraft. Suppose a spacecraft with a mass of 2.50 x 10 kg has a solar sail made of perfectly reflective aluminized film with an area of 2.59 x 106 m2 (about 1 square mile). If the spacecraft is launched into earth orbit and then deploys its sail at right angles to the sunlight, what is the acceleration due to sunlight? (At the earth's distance from the sun, the pressure exerted by sunlight on an absorbing surface is 4.70 x 10- Pa.) SOLUTION SET UP We sketch the situation in (Figure 1). Because our sail is perfectly reflective, the pressure exerted on it is twice the value given in the statement of the problem: p = 9.40 x 10° Pa. Before the sail is deployed, the spacecraft's net radial velocity relative to the sun is zero. SOLVE The radiation pressure p is the magnitude of force per unit area, so we start by finding the magnitude F of force exerted on the sail: F=pA= (9.40 x 10-6 N/m²)(2.59 x 106 m²) = 24.3 N We now find the magnitude a of the spacecraft's acceleration due to the radiation pressure. a=F/m= (24.3 N)/(2.50 x 104 kg) = 9.72 x 10-4 m/s2 REFLECT For this spacecraft, a square mile of sail provides an acceleration of only about 10 g, small compared with the accelerations provided by chemical rockets. However, rockets burn out; sunlight keeps pushing. Even on its first day, the craft travels more than 3000 km in the radial direction, and on day 12 its radial speed exceeds 1 km/s. Figure Part A - Practice Problem: < 1 of 1 > . What is the average magnitude of total force on these panels A = 2.59 x 106 m2 A communications satellite has solar-energy-collecting panels with a total area of 4.7 m associated with radiation pressure, if the radiation is completely absorbed? Express your answer to two significant figures and include appropriate units. ano Pressure = 940 x 10-6 Pa Value Units Submit Request Answer

Answer 1

Answer:-

Part (a)

The radiation on the absorbing surface (P) = 4.70 ×10^-6 pa

Total soil Area (A) = 4.7 m^2

Now,

Force on sail = pressure × Area

                    = (4.70 ×10^-6) ×(4.7) = 2.209 ×10^-5 Newtons

So, Force on soil = ( 2.0209 10^-5 N)

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