Answer:
15000N/m²
Explanation:
Given parameters:
Weight = 450N
Total area = 0.03m²
Unknown:
Pressure under her feet = ?
Solution:
Pressure is the force per unit area on a body.
Pressure =
Weight is a type of force;
Pressure = = 15000N/m²
a) See graph in attachment
b) The suvat equation to use is
c) The acceleration is
d) The acceleration is
e) The time needed is 8 s
Explanation:
a)
For this part, find in attachment the diagram representing this situation.
Since we are not given any particular direction for the motion, we choose the x-direction as the direction of motion of the boat.
Then we have the following:
- The initial position of the boat is , the origin
- The final position of the boat is
- The initial velocity of the boat is
- The final velocity of the boat is
Note that the arrow representing the final velocity is longer than that of the initial velocity, since the final velocity is larger.
b)
The motion of the speed boat is a uniformly accelerated motion (motion at constant acceleration), therefore we can use one of the suvat equations. In this particular problem, we know the following quantities:
, the initial velocity
, the final velocity
, the displacement of the boat
Therefore, the equation that best can be use to find the acceleration is
where
is the acceleration
c)
Now we have to solve the equation
In order to find the acceleration.
This can be done by dividing both terms by : this way, we find
And so the acceleration is
d)
Now we can use the equation found in part c) in order to find the acceleration.
We have the following data:
, the initial velocity
, the final velocity
, the displacement of the boat
And substituting into the equation,
e)
In order to find the time it takes the boat to travel the given distance, we can use the following suvat equation:
where:
is the initial velocity
is the final velocity
a is the acceleration
t is the time
Here we have:
Solving for t, we find:
Learn more about accelerated motion:
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