Answer:
The coupled velocity of both the blocks is 1.92 m/s.
Explanation:
Given that,
Mass of block A, 
Initial speed of block A, 
Mass of block B, 
Initial speed of block B, 
It is mentioned that if the two blocks couple together after collision. We need to find the common velocity immediately after collision. We know that due to coupling, it becomes the case of inelastic collision. Using the conservation of linear momentum. Let V is the coupled velocity of both the blocks. So,

So, the coupled velocity of both the blocks is 1.92 m/s. Hence, this is the required solution.
Answer: Rubidium has 5 orbits/shells/energy levels.
Explanation: It's electron configuration is as follows: 2-8-18-8-1.
P = density × gravity acceleration × height
P = 1200 × 9.81 × 15/100
P = 1765.8
Not what I'd call 'fast' at all.
Speed = (distance covered) / (time to cover the distance) .
Speed = (5 meters) / (10 seconds)
<em>Speed = 0.5 meter per second</em> .
That's like about 1.1 mile per hour .
Normal walking speed is considered to be around 1.4 m/s ... about 3.1 mph, or 14 meters in 10 seconds.
I've got a grandson who hasn't even turned 1 yet. He crawls and doesn't walk, but if you only cover 5m in 10s, he'd leave you in the dust pretty quick.