An explosion blows a rock into three parts. Two
parts go off at right angles to each other. These two are, 1
kg first part moving with a velocity of 12 ms–1
and 2 kg
second part moving with a velocity of 8 ms–1
. If the third
part flies off with a velocity of 4 ms–1
, its mass would be:
(a) 7 kg (b) 17 kg
(c) 3 kg (d) 5 kg
