Answer:
2. The metal surface exerts less frictional force because there are fewer bumps and irregularities on it than there are on the concrete.
Explanation:
Frictional force is a force that is exerted between two surfaces in contact with each other. Frictional force always opposes the direction of relative motion of the two surfaces: for instance, for a ball moving along a surface, the force of friction exerted by the surface on the ball points opposite to the direction of motion of the ball.
The magnitude of the frictional force for a ball moving on a flat surface is given by
where
is the coefficient of friction
m is the mass of the ball
g is the acceleration of gravity
The value of depends on the type of surface involved. In particular, a smooth surface has a smaller value of , while a rough surface will have a bigger value. In this case, we are comparing a smooth metal surface with concrete: since the metal surface has fewer bumps and irregularities than concrete, it has a smaller value of coefficient of friction, so it exerts less frictional force than concrete.
No. Sorry. A sound wave is a mechanical wave. There's nothing electromagnetic about it.
Answer:
Explanation:
Length of bar = L
mass of bar = M
mass of each ball = m
Moment of inertia of the bar about its centre perpendicular to its plane is
Moment of inertia of the two small balls about the centre of the bar perpendicular to its plane is
Total moment of inertia of the system about the centre of the bar perpendicular to its plane is
I = I1 + I2
Try B, it seems correct. I’m very sorry if i’m incorrect.
Iron rich minerals in rock pointed in one direction the switch to the exact opposite direction. I'd say that what supports this idea is that Earth's magnetic field goes through pole reversals.<span>
</span>
