Question

A force of 72 dyne is inclined to the horizontal at an angle of 60°. Find the acceleration in a mass of 9 g,
which moves in a horizontal direction.​

Answer 1

Explanation:

$\huge\bold\red{Answer:-}$

Acceleration in the mass is 0.04 m/s² [In S.I. unit]  

Explanation:-  

Here, we are given that a force of 72 dyne is inclined to horizontal at an angle of 60°.

So, firstly let's convert the units of force and mass of the body to S.I. unit.

 Force :-

⇒ 1 dyne = 10⁻⁵ N

⇒72 dyne = 72 × 10⁻⁵

⇒ 7.2×10⁻⁴ N  

Mass :-  

⇒ 1 g = 10⁻³ kg

⇒ 9g = 9×10⁻³ kg

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Since the force is inclined at an angle to the horizontal, thus horizontal component of the force will be :-  

Fₓ = F × cosθ

⇒ Fₓ = 7.2×10⁻⁴×cos60°

⇒ Fₓ = 7.2×10⁻⁴×0.5

⇒ Fₓ = 3.6×10⁻⁴ N

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Now, according to Newton's 2nd law of motion, acceleration of the mass will be :-  a = Fₓ/m

⇒ a = [3.6×10⁻⁴]/[9×10⁻³]

⇒ a = 0.4/10

⇒ a = 0.04 m/s²

Answer 2

SOLUTION

GIVEN THAT

• Force of 72 dyne is inclined to horizontal at an angle of 60°.

CONVERSION

FORCE

• 1 dyne = 10⁻⁵ N
• 72 dyne = 72 × 10⁻⁵
• 7.2×10⁻⁴ N

MASS

• 1 g = 10⁻³ kg
• 9g = 9×10⁻³ kg

CALCULATION

Force is inclined at an angle to the horizontal, thus horizontal component of the force will be :-

• Fₓ = F × cosθ
• Fₓ = 7.2×10⁻⁴×cos60°
• Fₓ = 7.2×10⁻⁴×0.5
• Fₓ = 3.6×10⁻⁴ N

Now, According to Newton's 2nd law of motion, acceleration of the mass will be :-

• a = Fₓ/m
• a = [3.6×10⁻⁴]/[9×10⁻³]
• a = 0.4/10
• a = 0.04 m/s²

RESULT

• Acceleration in the mass is 0.04 m/s²