Answer:
0.002833 sec
Explanation:
Speed of light in vacuum is 
Given distance = 850 km = 850×1000=850000 m
We have to calculate the time that light take to travel the distance 850 km
Time 
So the time taken by light to travel 850 km is 0.002833 sec
The gunstock it’s also called stock or shoulder stock
Answer:
<h2>The angular velocity just after collision is given as</h2><h2>
</h2><h2>At the time of collision the hinge point will exert net external force on it so linear momentum is not conserved</h2>
Explanation:
As per given figure we know that there is no external torque about hinge point on the system of given mass
So here we will have
now we can say
so we will have
Linear momentum of the system is not conserved because at the time of collision the hinge point will exert net external force on the system of mass
So we can use angular momentum conservation about the hinge point
Answer:
B- The amount of matter in a certain
amount of space
Explanation:
Density is the amount of matter an object has in a certain space. To find density, divide the mass of an object by the volume of an object.
Before solving this question, first we have to understand the special theory of relative.
As per classical mechanics, the velocity of light will be different in different frame of reference. The light moves in the ether medium which exists every where in the entire universe.
Let us consider a body which moves with a velocity v. Let light is coming along the direction of the body. As per classical mechanics,the velocity of light with respect to the body will be [ c-v].
Let us consider that light is coming from opposite direction. Hence, the velocity of light with respect to the observer will be c+v.
From above we see that velocity of light is different in both the cases which is wrong.
As per Einstein's special theory of relativity, the velocity of light will be same in every frame of reference i.e c=300000 km/s.
As per the question ,the space craft is moving with a velocity 0.1 c.
We are asked to calculate the velocity of the light with respect to an observer present in Mars.
Considering Einstein's theory of relativity, the velocity of light will be c [300000 km/s] with respect to the person in Mars.
