An object moving at a constant speed.
Frictional force offers the resistance to the applied force opposing its motion. Thus, it always acts in the direction opposite to that of the object in motion. If force is applied to the left, then friction acts in the right.
They all study under some sect of science.
And they all study under different sects of science ie. Biologist study of life Geologists study of Geology, and Physicists study of physics.
Answer:
The speed of the cart and clay after the collision is 50 cm/s .
Explanation:
Given :
Mass of lump , m = 500 g = 0.5 kg .
Velocity of lump , v = 30 cm/s .
Mass of cart , M = 1 kg .
Velocity of cart , V = 60 cm/s .
We know by conservation of momentum :

Here ,
is the speed of the cart and clay after the collision .
Putting all value in above equation .
We get :

Hence , this is the required solution .
The question is asking to describe and state and calculate what do the observer on the earth measure for the speed of the laser beam, and base on my research, the answer would be v = 1bc, I hope you are satisfied with my answer and feel free to ask for more