Answer:
a) t = 1.75 s
b) x = 31.5 m
Explanation:
a) The time at which Tom should drop the net can be found using the following equation:
Where:
: is the final height = 0
y₀: is the initial height = 15 m
g: is the gravity = 9.81 m/s²
: is the initial vertical velocity of the net = 0 (it is dropped from rest)
Hence, Tom should drop the net at 1.75 s before Jerry is under the bridge.
b) We can find the distance at which is Jerry when Tom drops the net as follows:
Then, Jerry is at 31.5 meters from the bridge when Jerry drops the net.
I hope it helps you!
Answer:
What is the problem I cant help unless you have the problem.
Explanation:
The release of free energy drives the spontaneous reaction.
Spontaneity can be <span>determined
using the change in </span>Gibbs free energy
(the thermodynamic potencial):
delta G=delta H – T*delta
S
where delta H is the enthalpy and delta S is the entropy.
The direction (the sign) of delta G depends of the changes
of enthalpy and entropy. If delta G is negative then the process is
spontaneous.
In our case, both delta H and delta S are negative values, the
process as said is spontaneous which means that it may proceed in the forward
direction.
The momentum of an object is given by the product between its mass and its velocity:
where m is the mass and v the velocity.
For the object in our problem, m=10 kg and v=10 m/s, therefore its momentum is
So, the correct answer is B).
Answer:
a.
b.
c. 
d. The angular acceleration when sitting in the middle is larger.
Explanation:
a. The magnitude of the torque is given by 
, being r the radius, F the force aplied and 
the angle between the vector force and the vector radius. Since 
and so 
.
b. Since the relation 
hols, being I the moment of inertia, the angular acceleration can be calculated by 
. Since we have already calculated the torque, all left is calculate the moment of inertia. The moment of inertia of a solid disk rotating about an axis that passes through its center is 
, being M the mass of the disk. If we assume that a person has a punctual mass, the moment of inertia of a person would be given by 
, being 
the mass of the person and 
the distance from the person to the center. Given all of this, we have
.
c. Similar equation to b, but changing 
, so
.
d. The angular acceleration when sitting in the middle is larger because the moment of inertia of the person is smaller, meaning that the person has less inertia to rotate.
