Question
Fig. 11.1 represents the Earth in orbit around the Sun.
(a) (i) State the name of the force that keeps the Earth in orbit around the Sun.
……………………………………………………………………………………………………………………. [1]
(ii) State the time taken by the Earth to complete one orbit of the Sun. Include the unit.
time for one orbit = ………………………………………………… [1]
(iii) State the time taken by the Earth to rotate once on its axis. Include the unit.
time for one rotation = ………………………………………………… [1]
(iv) The Sun consists mainly of two gases. State the names of the two gases.
……………………………………………………… and ……………………………………………………… [2]
(b) (i) Most of the radiation from the Sun consists of visible light and two other regions of the electromagnetic spectrum.
State the name of one of the other two regions. \([1]\)
(ii) The speed of visible light is \(3.0 \times 10^8 \mathrm{~m} / \mathrm{s}\).
Calculate the time taken for visible light to travel from the Sun to the Earth when the Earth is in the position shown in Fig. 11.1.
time taken \(=\)s [3]
▶️Answer/Explanation
Ans:
a)(i) gravitational (attraction)
(a)(ii) 365 (¼) days
(a)(iii) 24 hours
(a)(iv) helium
hydrogen
(b)(i) infrared OR ultraviolet
(b)(ii) 500 (s)
$1.5 \times 10^{11} /3.0 \times 10^8$
(time =) distance / speed