How does an octopus or a squid uses Newton's third law of motion to escape from enemies
1 answer:
You might be interested in
First you need to draw the picture of the problem to better understand it. Like the one bellow.
In this task you have 2 sides of triangle and we can calculate angle between them. Angle between them is 120 - 35 = 85 degrees.
Once you have those 3 variables you can calculate third side of triangle using cosine law.
a - second displacement
b - first displacement
c- resultant displacement.
now we just need to calculate this.
a = 196
now, we use cosine law again to find the angle between second and first displacement.
degrees
The angle marked with "?" in the graph is our direction angle. We will call it
Second displacement has magnitude of 196 and a direction of -14.64 with positive x axis
In this task you have 2 sides of triangle and we can calculate angle between them. Angle between them is 120 - 35 = 85 degrees.
Once you have those 3 variables you can calculate third side of triangle using cosine law.
a - second displacement
b - first displacement
c- resultant displacement.
now we just need to calculate this.
a = 196
now, we use cosine law again to find the angle between second and first displacement.
The angle marked with "?" in the graph is our direction angle. We will call it
Second displacement has magnitude of 196 and a direction of -14.64 with positive x axis
Let's call h the initial height of the rock (h=50 m, the height of the bridge).
Initially, the rock has only gravitational potential energy, which is given by
where m=10 kg is the mass of the rock while g is the gravitational acceleration. So, the total mechanical energy of the rock at this point is
At midway point of its fall, its height is
, so its potential energy is
But now the rock is also moving by speed v, so it also has kinetic energy:
So the total energy at the midway point of the fall is
(1)
The mechanical energy must be conserved, so
, so we can rewrite (1) and solve it to find the kinetic energy of the rock at midway point of its fall:
Initially, the rock has only gravitational potential energy, which is given by
where m=10 kg is the mass of the rock while g is the gravitational acceleration. So, the total mechanical energy of the rock at this point is
At midway point of its fall, its height is
But now the rock is also moving by speed v, so it also has kinetic energy:
So the total energy at the midway point of the fall is
The mechanical energy must be conserved, so