Question 149: Laws of Motion

Question

A spring balance is attached to the ceiling of a lift. A man hangs his bag on the spring and the spring reads $$49$$ $$N,$$ when the lift is stationary. If the lift moves downward with an acceleration of $$5 m/{s^2}$$, the reading of the spring balance will be

Accepted Answer

When lift is stationary then,
T
1
= $$mg$$ = 49 N
$$m$$ = 5
For the bag accelerating down
$$mg-T=ma$$
$$	herefore$$ $$T=m(g-a)$$
$$ = 5\left( {9.8 - 5} ight) = 24\,N$$

Answer

$$24$$ $$N$$

Answer

$$74$$ $$N$$

Answer

$$15$$ $$N$$

Answer

$$49$$ $$N$$

Laws of Motion

A spring balance is attached to the ceiling of a lift. A man hangs his bag on the spring and the spring reads $49 N, when the lift is stationary. If the lift moves downward with an acceleration of 5 m/{s^2}$, the reading of the spring balance will be

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