Advertisements
Advertisements
प्रश्न
Suppose the ceiling in the previous problem is that of an elevator which is going up with an acceleration of 2.0 m/s2. Find the elongation.
Advertisements
उत्तर
When the ceiling of the elevator is going up with an acceleration 'a', then a pseudo-force acts on the block in the downward direction.
a = 2 m/s2
From the free-body diagram of the block,
kx = mg + ma
⇒ kx = 2g + 2a
= 2 × 9.8 + 2 × 2
= 19.6 + 4
\[\Rightarrow x = \frac{23 . 6}{100} = 0 . 236 \approx 0 . 24 \text{ m }\]
When 1 kg body is added,
total mass = (2 + 1) kg = 3 kg
Let elongation be x'.
∴ kx' = 3g + 3a = 3 × 9.8 + 6
\[ = 0 . 354 \approx 0 . 36 m\]
So, further elongation = x' − x
= 0.36 − 0.24 = 0.12 m.
APPEARS IN
संबंधित प्रश्न
Two objects A and B are thrown upward simultaneously with the same speed. The mass of A is greater than that of B. Suppose the air exerts a constant and equal force of resistance on the two bodies.
A person says that he measured the acceleration of a particle to be non-zero even though no force was acting on the particle.
Let m1 = 1 kg, m2 = 2 kg and m3 = 3 kg in the following figure. Find the accelerations of m1, m2 and m3. The string from the upper pulley to m1 is 20 cm when the system is released from rest. How long will it take before m1 strikes the pulley?
A monkey is climbing on a rope that goes over a smooth light pulley and supports a block of equal mass at the other end in the following figure. Show that whatever force the monkey exerts on the rope, the monkey and the block move in the same direction with equal acceleration. If initially both were at rest, their separation will not change as time passes.
The monkey B, shown in the following figure, is holding on to the tail of monkey A that is climbing up a rope. The masses of monkeys A and B are 5 kg and 2 kg, respectively. If A can tolerate a tension of 30 N in its tail, what force should it apply on the rope in order to carry monkey B with it? Take g = 10 m/s2.
The linear momentum of a body of mass m moving with velocity v is :
Calculate the magnitude of force which when applied on a body of mass 0.5 kg produces an acceleration of 5 m s-2.
A force of 10 N acts on a body of mass 2 kg for 3 s, initially at rest. Calculate : The velocity acquired by the body
Prove mathematically F = ma
Multiple Choice Question. Select the correct option.
The impulse of a body is equal to:
Which of the following has the largest inertia?
A ball is thrown upward and reaches a maximum height of 19.6 m. Find its initial speed?
What do you mean by the conservation of momentum? Briefly, explain the collision between two bodies and the conservation of momentum.
A hockey player is moving northward and suddenly turns westward with the same speed to avoid an opponent. The force that acts on the player is ______.
A body of mass 2 kg travels according to the law x(t) = pt + qt2 + rt3 where p = 3 ms−1, q = 4 ms−2 and r = 5 ms−3. The force acting on the body at t = 2 seconds is ______.
A woman throws an object of mass 500 g with a speed of 25 ms1.
- What is the impulse imparted to the object?
- If the object hits a wall and rebounds with half the original speed, what is the change in momentum of the object?
According to Newton's Second Law of Motion, what quantity is directly proportional to the applied force?
How does moving your hand backward while catching a cricket ball reduce pain?
