Answer:it is 343 meter per second in air.
Explanation:
it is 5 times more in liquids than in gases and 15 times more in solids than in gases.In air it is affected by various physical conditions such as pressure,humidity and temperature.
Conductivity is required for the electric current to flow.
Answer:
0.64 m
Explanation:
The first thing is calculate the center of mass of the system.

now multiplying every coordinate x by the mass of each object (romeo, juliet and the boat) and dividing all by the total mass taking by reference the position of juliet.

X_cm = 1.4589 m
When the forces involved are internals, the center of mass don't change
After the movement the center of mass remains in the same distance from the shore, but change relative to the rear of the boat.

X_cm= 2.10 m
this displacement is how the boat move toward the shore.
2.10-1.46= 0.64 m
Answer:
The coefficient of kinetic friction = 0.026
Explanation:
An 56 kg sled is being pulled across the snow, at constant speed,by a horizontal force of 15 N.
Here we have to note that the weight is pulled at a constant speed . This means that the net force acting on the weight is zero.
The external force acting on the body is in the forward direction and the friction acts in the backward direction.
Friction increases as the mass of the body increases.
Friction = 
We now equate this to the external force of 15 N.
15 = 
= 
= 0.026
The coefficient of kinetic friction = 0.026