B is the answer because it causes impact and collides together.
Answer: 10 m/s
We're told the speed is constant, so it's not changing throughout the time period given to us. So throughout the entire interval, the speed is 10 m/s.
Answer:
(a) 
(b) 
Explanation:
(a) Since a constant external force is applied to the body, it is under an uniformly accelerated motion. Using the following kinematic equation, we calculate the final velocity of the mass if it is initially at rest(
):

According to Newton's second law:

Replacing (2) in (1):

(b) In this case we have
. So, we use the final velocity equation:

Factor out 8 and then facotr and u get
8/9(9x+1)(9x-1
You sure wouldn't want something like cm/s or (yikes cm/hr). You want a reasonable number for sports usually between 0 and 100
Km / hour would be a good choice.
The next town to where I live is 25 km away. On a good day, I can make it there in about 3/4 of an hour.
Speed = 25 km / 0.75 hour = 33.3 km/hour. That's actually a little fast most of the time. But you should understand what I mean.