This is A.) lake. A river is a small amount of water that isn't always fresh water. A stream is too small. And an ocean is made of salt water.
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.
Answer:
The number of people at game are approximately 22909
Explanation:
Given data
When one person shout 
When n number of person shout together 
The sound intensity level during one person shout is given by:

The sound intensity level during n number of person shout is given by:

Since each person generates same sound intensity and hence total number of persons can be determined as

Hence
The number of people at game are approximately 22909
Answer:
Reduce its weight
Explanation:
For an object on a flat surface, the maximum force of friction experienced by the object is given by:

where
is the coefficient of friction
W is the weight of the object
As we can see from the formula, there are two ways of reducing the friction:
- Decreasing
--> this coefficient depends on the material and on the roughness of the surface, so this can be changed by changing the properties of the surface
- Decreasing W, the weight --> this can be done by reducing the mass of the object
Net force acting on the car is 3 x 10^3 Newtons: