Question

The ratio of weights of a man in a lift moving with accelration 'a' in upward direction and moving with acceleration 'a' in downward direction is 3:1 .Then the value of a is :- (1) (g)/(3) (2) (g)/(2) (3) (g)/(5) (4) (4)/(3)g​

Answer 1

Answer:

g/2

Explanation:

Accelerating upward:

Weight = mg + ma

Accelerating downward:

Weight = mg - ma

Ratio of weights is 3:1,

=> (mg + ma)/(mg - ma) = 3/1

=> (g + a)/(g - a) = 3/1

=> g + a = 3(g - a)

=> a + 3a = 3g - g

=> 4a = 2g

=> 2a = g

=> a = g/2

Answer 2

Answer:

✯ Given :-

• The ratio of weight of a man in a lift moving with acceleration 'a' in upward direction and moving with acceleration'a'in downward direction is 3:1 .

✯ To Find :-

• What is the value of a .

✯Formula Used :-

✬ Accelerating Upward ✬

$\large\purple{\underline{\boxed{\textbf{Weight\: =\: mg\: +\: ma}}}}$

✬ Accelerating Downward ✬

$\large\purple{\underline{\boxed{\textbf{Weight\: =\: mg\: -\: ma}}}}$

✯Solution :-

⋆ Given :

• Ratio = 3:1

➣ According to the question by using the formula we get,

↦ $\dfrac{(mg + ma)}{(mg - ma)}$ = $\dfrac{3}{1}$

↦ $\dfrac{(g + a)}{(g - a)}$ = $\dfrac{3}{1}$

➙ By doing cross multiplication we get,

↦ g + a = 3(g - a)

↦ g + a = 3g - 3a

↦ a + 3a = 3g - g

↦ 4a = 2g

↦ a = $\dfrac{2g}{4}$

➥ a = $\dfrac{g}{2}$

$\therefore$ The value of a is $\boxed{\bold{\large{\dfrac{g}{2}}}}$

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