Describe how excavations are done.
1 answer:
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The car A has a mass of 1200 kg.
The car B has the mass of 1900 kg.
It is given that velocity of car A is given as 22 Km/hr
The car B has the velocity of 25 Km/hr.
Let the mass of two bodies are denoted as
Let the velocity of cars A and B are denoted as
The momentum before collision is-
[Here p stand for momentum.]
We are asked to calculate the final momentum of the system after collision.
The answer of the question is based law of conservation of linear momentum.
As per law of conservation of linear momentum the sum total linear momentum for an isolated system is always constant.Hence irrespective of the type of collision[elastic and inelastic],the momentum of the system is always constant which is a universal truth.
Let after the collision the velocity of A and B are
Hence the final momentum of the system is-
As per the law of conservation of linear momentum, the initial and final momentum must be equal i.e
Hence the option A is right.
Answer:
16 J
Explanation:
It is given that,
Work done, W = 2 J
A spring is stretched by 2.0 cm from its equilibrium length
We need to find how much more work will be required to stretch it an additional 4.0 cm.
Let k is the spring constant of the spring. When W = 2J, and x = 2 cm, then energy required to stretch the spring is :
The energy required to stretch the spring from 2 cm to additional 4 cm i.e. 2+4= 6 cm.
So, the required work done is 16 J.