Answer:
1.8*10^8m/s
Explanation:
Using
L= lo√1-v²/c²
So making v subject we have
V= c√1-4.8²/6²
V= 0.6*c
V= 0.6*3E8m/s
V= 1.8*10^8m/s
A. Balloons can be filled with air.
C. Air has mass.
Answer:
(a) 
(b) 5220 j
(c) 1740 watt
(d) 3446.66 watt
Explanation:
We have given mass m = 290 kg
Initial velocity u = 0 m/sec
Final velocity v = 6 m/sec
Time t = 3 sec
From first equation of motion
v = u+at
So 
(a) We know that force is given by
F = ma
So force will be 
(b) From second equation of motion we know that

We know that work done is given by
W = F s = 580×9 =5220 j
(c) Time is given as t = 3 sec
We know that power is given as

(d) Time t = 1.5 sec
So 