Answer:
It's option d - Negative acceleration
Explanation:
- Let's start by demonstrate why <em>it's not option b - Speed : </em>Speed is a scalar quantity so it can not be represented by a vector
- Let's check that <em>the green vectors represent velocity</em> (velocity is a vector quantity, velocity is a direction aware, while speed is just a scalar)
- Now let's show that the circled vectors are acceleration vectors:
Mathematically position X , velocity V and acceleration A are:
and 
Where X, V, A are vectors and
indicates the derivate a of a time is equal to b.
So, this show that acceleration is a rate respect of time of velocity ⇒ When acceleration is positive, velocity increments, when acceleration is negative, velocity decrements.
<em>The above explanation correspond to the motion map shown, getting demonstrated that the answer is D - Negative acceleration </em>
Answer:
The rate of change of distance between the two ships is 18.63 km/h
Explanation:
Given;
distance between the two ships, d = 140 km
speed of ship A = 30 km/h
speed of ship B = 25 km/h
between noon (12 pm) to 4 pm = 4 hours
The displacement of ship A at 4pm = 140 km - (30 km/h x 4h) =
140 km - 120 km = 20 km
(the subtraction is because A is moving away from the initial position and the distance between the two ships is decreasing)
The displacement of ship B at 4pm = 25 km/h x 4h = 100 km
Using Pythagoras theorem, the resultant displacement of the two ships at 4pm is calculated as;
r² = a² + b²
r² = 20² + 100²
r = √10,400
r = 101.98 km
The rate of change of this distance is calculated as;
r² = a² + b²
r = 101.98 km, a = 20 km, b = 100 km

Answer:
54%
Explanation:
We are given that
S.D=4.2 lb
Mean=
We have to find the percentage of household throw out at least 9 lb of paper a week.
Normal distribution formula :

We have a=9


%
Hence, the percentage of household throw out at least of paper a week=54%
Well, I think the answer would be 4 meters because the speed is in meters per second and the frequency is 5 waves every 2 seconds.
Wavelength = Speed/Frequency
I think the frequency is 2.5 waves a second but that's not something I'm 100% sure about.
I hope this helps though.