<span>According to Newton's first law of motion:
-- objects at rest will remain at rest unless acted upon by an outside force
-- objects in motion will remain in motion unless acted upon by an outside force
</span>
Answer:
A lens placed in a transparent liquid becomes invisible because when refractive index of the material of the lens is equal to the refractive index of the liquid in which lens is placed under this condition no bending of light takes place when it travels from liquid to the lens, so both will start behaving like both are same things.
Explanation:
hope it helps :))
The change in momentum of the car is 6000 kg m/s
Explanation:
According to the impulse theorem, the change in momentum of an object is equal to the impulse exerted on the object, therefore:
where
is the change in momentum
I is the impulse exerted
For the car in this problem, the impulse received is
I = 6000 kg m/s (in the forward direction)
Therefore, the change in momentum of the car is equal to this value:
(in the forward direction)
We can also calculate what is the new momentum of the car. In fact, the initial momentum is
And so, the new momentum is
Learn more about impulse and momentum:
brainly.com/question/9484203
#LearnwithBrainly
Echoes occur when a reflected soundwave reaches the ear more than 0.1 seconds after the original sound wave was heard. ... There will be an echoinstead of a reverberation. Reflection of sound waves off of surfaces is also affected by the shape of the surface.
(mark as brainly please)
<h2>
Answer: 13.61 N/m</h2>
Hooke's law establishes that the elongation of a spring is directly proportional to the modulus of the force 
applied to it, <u>as long as the spring is not permanently deformed</u>:
(1)
Where:
is the elastic constant of the spring. The higher its value, the more work it will cost to stretch the spring.
is the length of the spring without applying force.
is the length of the spring with the force applied.
According to this, we have a spring where only the force due gravity is applied.
In other words, the force applied is the weigth 
of the block:
(2)
Where 
is the mass of the block and 
is the gravity acceleration.
(3)
(4)
Knowing the force applied and 
and 
, we can substitute the values in equation (1) and find :
(5)
(6)
<u>Finally:</u>
