Question

W= FS cosØ
F= 9.34N
S=63m
Angle Of Displacement= 30°

I AM A 9TH CLASS STUDENT I DON'T KNOW WHAT IS Cos..help me​

Answer 1

Firstly, cos is a trigonometric function.

The Formula for work is FScos∅

where it is given that ∅ = 30°

The value of cos30° is √3/2

Now,

Work = FScos∅

=>9.34×63m×√3/2

=>4.67×63×√3

=>294.21√3 Joule

=>508.9Joule ~ 509Joule

{value of √3 is 1.73 so, evaluating 294.21√3 we get 508.933}

[Ps:- You don't have to worry about their values, also, generally the values of 90°, 0° or 180° comes in examinations of 9th, so just learn their values which is 0,1,-1 respectively. If given otherwise, the values will be stated already]

Cheers!

Answer 2

W ≈ 510 J

W = FS CosΦ

W = 9.34 N × 63m × cos30°

W = 9.34 N× 63m × √3/2

W = 9.34N × 63m × 1.732/2

W = 509.57 J

W ≈ 510 J

Hello!

Welcome to the concept of trigonometry

Trigonometry

It is a branch of mathematics, which deals with the measurements of a three angles

'Trigono' - Three

'metry' - measure

Trigonometry mainly deals with Right angled triangle

There are six trigonometric ratios Which are also called as the roots of trigonometry!

They are

Sin

Cos

tan

cot

sec

cosec

The unknown angle of the triangle be 'Theta' (Φ)

consider a right angled triangle

$sin \theta = \dfrac{Opposite side }{Hypoteneuse}$

$\boxed{\green{cos \theta = \dfrac{Adjacent side }{Hypoteneuse}}}$

$tan \theta = \dfrac{Opposite side }{Adjacent side}$

$cot\theta = \dfrac{Adjacent side}{Opposite side}$

$cosec \theta = \dfrac{ Hypoteneuse}{Opposite side}$

$sec \theta = \dfrac{ Hypoteneuse}{Adjacent}$

These are called as trigonometric ratios, which are also the basic things in the topic.

You will, know more about it in the higher classes!..