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**Need help with part B only** Most geologists believe that the dinosaurs became

ID: 1342236 • Letter: #

Question

**Need help with part B only**

Most geologists believe that the dinosaurs became extinct 65 million years ago when a large comet or asteroid struck the earth, throwing up so much dust that the sun was blocked out for a period of many months. Suppose an asteroid with a diameter of9.0 km and a mass of 1.0×1015 kg hits the earth with an impact speed of 4.5×104 m/s .

A)What is the earth's recoil speed after such a collision? Assume that the mass of the earth is5.981024 kg. (Use a reference frame in which the earth was initially at rest.) ANSWER: 7.53x10^-6 m/s

B) What percentage is this of the earth's speed around the sun? Assume that the orbit of the earth is a circle with the radius of 1.51011 m. Answer is v recoill/v orbital as a percentage.

Explanation / Answer

Here ,

B)

as radius of earth , r = 1.5 *10^11

as time period , t = 365 days

t = 365 * 3600 * 24

t = 3.153 *10^7 s

Now , speed of earth around sun ,ve = 2 * pi * r/t

ve = 1.5 * 10^11 * 2pi/(3.152 *10^7)

ve = 29895 m/s

Now , percentage = (7.53 *10^-6/29895) * 100

percentage = 2.518 *10^-8 %

this is 2.518 *10^-8 percent of the earth's speed around the sun