Answer:
Sea-floor spreading occurs in the oceanic ridges. In there, volcanic activity, together with the gradual movement of the bottom, form new oceanic crust. This allows a better understanding of the continental drift explained by the theory of plate tectonics.
The greatest evidence for Sea-floor spreading is the oceanic trenches, the oceanic ridges, the magma protruding to the surface and the new seafloor.
In previous theories, continents were assumed to be transported across the sea. Harry Hess, in the 1960s, proposed the idea that the seabed itself moves as it expands from a central point. The theory is now accepted, and the phenomenon is thought to be caused by convection currents in the upper layer of the mantle.
Answer:
the initial velocity of the ball is 104.67 m/s.
Explanation:
Given;
angle of projection, θ = 60⁰
time of flight, T = 18.5 s
let the initial velocity of the ball, = u
The time of flight is given as;

Therefore, the initial velocity of the ball is 104.67 m/s.
Answer:
The electric potential in volts is 1.618 x 10⁻¹⁷ V
Explanation:
The electric potential, in volts, at point P, can be calculated as follow;
Electric potential is the work done in moving a unit positive charge from infinity to a particular point in the electric field.
Thus, the work done in this process in moving the charge to point p is 101eV.
Convert this Volts = 101 × 1.602 x 10⁻¹⁹ V
= 1.618 x 10⁻¹⁷ V
Therefore, the electric potential in volts is 1.618 x 10⁻¹⁷ V
Answer:
The boat will move in the direction of the force exerted.
Explanation:
To describe the motion of the boat, we shall first obtain the net force acting on the boat. This can be obtained as illustrated below:
From the question given above, the following data were obtained:
Force exerted (Fₑ) = 300 N
Resistive force (Fᵣ) = 250 N
Net force (Fₙ) =?
Fₙ = Fₑ – Fᵣ
Fₙ = 300 – 250
Fₙ = 50 N
Thus, the net force acting on the boat is 50 N in the direction of the force exerted.
Since the net force is in the direction of the force exerted, the boat will move in the direction of the force exerted..!
Acceleration = change in velocity/time
By F = ma,
6 = 33 x change in velocity / 9
change in velocity = +1.636 m/s