Question

8. How much will a person with 72 N weight on Earth, weigh on the moon?

(a) 12 N (b) 36 N (c) 21 N (d) 63 N

9. At what distance should a watchmaker hold his lens from the watch?

(a) At the focal length (b) At less than focal length

(c) At more than the focal length (d) At zero distance

Answer 1

8.as the weight on moon is 1/6 in that of earth so a person weighing 72 N will weigh ,
72 × 1/6 = 12

Answer 2

8. (a) 12 N {since, the weight at moon is 1/6 the weight on earth ]

9. (b) at less than focal length