Answer:
An earthquake is a trembling movement of the earth's crust. These tremors are generally caused by shifts of the plates that make up the earth's surface. ... A tsunami (pronounced soo-NAHM-ee) is a series of huge waves that occur as the result of a violent underwater disturbance, such as an earthquake or volcanic eruption.
Explanation:
The Earth takes (365 and 1/4) days to orbit the sun. That's the length of our 'year'.
Since it's not really possible to make our calendar a quarter of a day longer every year, we make the calendar a <u><em>whole</em></u> day longer every 4 years.
So "Leap years" make up for the extra one-fourth day the Earth takes to orbit the sun.
Answer:
The answer is "between 20 s and 30 s".
Explanation:
Calculating the value of positive displacement:


Calculating the value of negative displacement upon the time t:




That's why its value lie in "between 20 s and 30 s".
With that information you can only suppose a uniformly accelerated motion. This is, acceleration is constant.
Then, acceleration = change in velocity / change in time = (58 -54)km/h / 2 h = 4km/h / 2 h = 2 km/h^2
Then the equation for velocity, V is
V = Vo + a*t = Vo + 2 (km/h^2) * t = Vo + 2t
Vo is the initial velocity, which you can find using V = 54km/h and t = -2
Vo = V after 2 hours - a*(2hours) = 54km/h - 2(km/h^2)*2h = 54km/k - 4km/h = 50km/h
Then, the equation is: V = 50 km/h + 2t
Valid for constant acceleration.
SONAR stands for "sound navigation and ranging,” and it is used to map and explore the ocean floor.