Decompose each velocity in its i and j - coordinates.
1) River's velocity
3.5 m/s, west fo east = 3.5i + 0j
2) Luke's velocity
5m/s, 60° east of north
5* sin(60°) i + 5*cos(60°) j = 4.33 i + 2.5 j
3) Resultant velocity
[3.5i + 0j] + [4.33i + 2.5j] = 7.83i + 2.5j
resultant speed = √[ (7.83)^2 + (2.5)^2 ] = 8.22 m/s
angle = arctan(2.5 / 7.83) = 17.7° north of east (equal to 72.3° east of north).
The sum of the first four terms of the sequence is 22.
In this question,
The formula of sum of linear sequence is
The sum of the first ten terms of a linear sequence is 145
⇒ 
⇒ 145 = 5 (2a+9d)
⇒ 
⇒ 29 = 2a + 9d ------- (1)
The sum of the next ten term is 445, so the sum of first twenty terms is
⇒ 145 + 445
⇒ 
⇒ 590 = 10 (2a + 19d)
⇒ 
⇒ 59 = 2a + 19d -------- (2)
Now subtract (2) from (1),
⇒ 30 = 10d
⇒ d = 
⇒ d = 3
Substitute d in (1), we get
⇒ 29 = 2a + 9(3)
⇒ 29 = 2a + 27
⇒ 29 - 27 = 2a
⇒ 2 = 2a
⇒ a = 
⇒ a = 1
Thus, sum of first four terms is
⇒ 
⇒ 
⇒ S₄ = 2(2+9)
⇒ S₄ = 2(11)
⇒ S₄ = 22.
Hence we can conclude that the sum of the first four terms of the sequence is 22.
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Answer:
D
Step-by-step explanation:
Linear Functions will never have curve lines in the graph.
The area are in the ratio of the squares of corresponding sides.
That is 15^2 : 20^2 = 225:400
so the area of the smaller figure = (225/400) * 64
= 0.5625 * 64
= 36 cm^2 (answer)
The number of different three-digit numbers that can be set for the combination lock is 125
<h3>How to determine the number of different locks?</h3>
The digits are given as
Digit = 1, 2, 3, 4, 5
Each digit can be repeated on the number lock.
So, the individual digit of the lock can be any of the 5 digits.
So, we have:
Locks = 5 * 5 * 5
Evaluate
Locks = 125
Hence, the number of different three-digit numbers that can be set for the combination lock is 125
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