Batman is fighting superman. He throws his 5 kg fist at superman with a speed of 9 m/s. Superman stops the punch with a force of
2 answers:
Answer:
It took seconds for batman's hand to stop moving.
Explanation:
Newton' s second law is defined as:
(1)
Where m is the mass and a is the acceleration.
But it is known that the acceleration is defined as follow by the kinematic equation that corresponds to a Uniformly Accelerated Rectilinear Motion.
(2)
Where is the final velocity and
is the initial velocity
The initial velocity of the fist will be zero () since it starts from a state of rest.
Then, equation 2 can be replaced in equation 1
(3)
Therefore, t can be isolated from equation 3
(4)
Hence, it took seconds for batman's hand to stop moving.
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<h2>Answer: (a)t=0.553s, (b)x=110.656m</h2>
Explanation:
This situation is a good example of the projectile motion or parabolic motion, in which the travel of the bullet has two components: x-component and y-component. Being their main equations as follows:
x-component:
(1)
Where:
is the bullet's initial speed
because we are told the bullet is shot horizontally
is the time since the bullet is shot until it hits the ground
y-component:
(2)
Where:
is the initial height of the bullet
is the final height of the bullet (when it finally hits the ground)
is the acceleration due gravity
Now, for the first part of this problem, the time the bullet elapsed traveling, we will use equation (2) with the conditions given above:
(3)
(4)
Finding :
(5)
Then we have the time elapsed before the bullet hits the ground:
(6)
For the second part of this problem, we are asked to find how far does the bullet traveled horizontally. This means we have to use the equation (1) related to the x-component:
(1)
Substituting the knonw values and the value of found in (6):
(7)
(8)
Finally: