Answer:
<em>The correct difference is 3.44 ft</em>
Explanation:
The correct difference is given as
D=R_A-R_B
D=9.09-5.65
D=3.44 ft
The trigonometric ratios are sine, cosine and tangent. We can use cosine to find the length of the shadow from the calculation as 1.7 ft.
<h3>What is trigonometric ratio?</h3>
The term trigonometric ratio has to do with sine, cosine and tangent which are used to solve problems that involve the right angled triangle.
Using the geometry of the right angle triangle, we can find the tangent of the angle 30 in order to obtain the length of the shadow.
Tan 30° = opp/3
opp = 3Tan 30°
opp = 1.7 ft
The length of the girl's shadow from the calculation is 1.7 ft.
Learn more about tangent: brainly.com/question/14022348
Answer:
15 m/s
Explanation:
Speed(m/s) = distance(m)/time(s)
distance = 216 km = 216,000 m
time = 4 hours = 14,400 s
speed = 216000/14400 = 15 m/s
The work done by the applied force on the block against the frictional force is 15.75 J.
<h3>
Work done by the applied force</h3>
The work done by the applied force is calculated as follows;
W = Fd
F - Ff = ma
where;
- F is applied force
- Ff is frictional force
Fcos(37) - μmgsin(37) = ma
Fcos(37) - (0.3)(4)(9.8)sin(37) = 4(0.2)
0.799F - 7.077 = 0.8
F = 9.86 N
W = Fdcosθ
W = 9.86 x 2 x cos(37)
W = 15.75 J
Thus, the work done by the applied force on the block against the frictional force is 15.75 J.
Learn more about work done here: brainly.com/question/25573309
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