Answer:
The slope of a position-time graph can be calculated as:

where
is the increment in the y-variable
is the increment in the x-variable
We can verify that the slope of this graph is actually equal to the velocity. In fact:
corresponds to the change in position, so it is the displacement, 
corresponds to the change in time
, so the time interval
Therefore the slope of the graph is equal to

which corresponds to the definition of velocity.
Momentum is conserved throughout this scenario.
Before the man does anything, the total momentum of him and his book is zero. So we know that it'll be zero after he throws the book.
Momentum = (mass) x (velocity)
The man gives the book (1.2 kg)x(10 m/s north) = 12 kg-m/s north
of momentum.
Since the total momentum must be zero, the man himself picks up 120 kg-m/s of momentum south.
(his mass)x(his v) = 120 kg-m/s south = (770 kg-m/s^2/9.8 m/s^2)x(V).
His velocity southward = (120 x 9.8) / (770) m/s .
He needs to reach the shore 10m away.
Time = distance/speed
= (10 x 770) / (120 x 9.8) seconds
= 6.55 seconds
Answer:
Why do scientists usually talk about mass rather than weight? An object's weight is dependent on its mass and how strongly gravity pulls on it. The strength of gravity depends on how far away one object is from another. That's why the same object weighs different amounts on different planets.
Explanation: on Google
The choices for this question can be found elsewhere and as follows:
short hill.
tall hill.
tightly coiled spring.
<span>stretched-out spring.
</span>
I think the best answer is the third option. A high amplitude sound wave can best be compared to a tightly coiled spring. <span>A </span>high<span> energy </span>wave<span> is characterized by having a </span><span>high amplitude.</span>