Which method is used to counteract the effects of erosion caused by water
1 answer:
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Answer:
e) 120m/s
Explanation:
When the ball reaches its highest point, its velocity becomes zero, meaning
.
where is the initial velocity.
Solving for we get
which is the time it takes the ball to reach the highest point.
Now, after the ball has reached its highest point, it turns around and falls downwards. After time since it had reached the highest point, the ball has traveled downwards and the velocity
it has gained is
,
and we are told that this is twice the initial velocity ; therefore,
which gives
Thus, the total time taken to reach velocity is
This , we are told, is 36 seconds; therefore,
and solving for we get:
which from the options given is choice e.
ANSWER
C. . newtons
EXPLANATION
According to Newton's second law,
, where
is the mass measured in kilograms.
and
is the acceleration in metres per second square.
We substitute these values to obtain,
.
We rearrange to get,
.
We multiply out the first two numbers and leave our answer in standard form to get,
.
The correct answer is C
Answer:
For the first situation, we first need to find the mass of the second train car.
In order to do that, we apply the conservation of the amount of movement:
and we have as a result:
m2 = 289.6875
For the second situation, also we will apply the conservation of the amount of movement:
and we have as a result:
V = 2.64 (it is moving to the right)