(c) A vehicle moving with a speed of 18 km h–1 covers….m in 1
(d) The relative density of lead is 11.3. Its density is ….g cm–3 or ….kg m–3.
Answer:
(c) Given, speed of the vehicle = 18 km/h
We know that 1 km = 1000 m and 1 hr = 60 x 60 = 3600 s
Therefore, 1 km/hr = 1000 m/3600 s
1 km/hr = 5/18 m/s
Similarly, 18 km/h = (18 x 1000)/3600
!8km/h = 5 m/s
Therefore, the distance travelled by the vehicle in 1 s is 5 m.
(d) Given that the relative density of lead is 11.3 g cm-3
=> 11.3 x 103 kg m-3
We know that 1 kilogram = 103g, 1 meter = 102 cm
Therefore, 11.3 x 103 kg m-4