Answer:
The sled needed a distance of 92.22 m and a time of 1.40 s to stop.
Explanation:
The relationship between velocities and time is described by this equation: 
, where 
is the final velocity, 
is the initial velocity, 
the acceleration, and 
is the time during such acceleration is applied.
Solving the equation for the time, and applying to the case: 
, where 
because the sled is totally stopped, 
is the velocity of the sled before braking and, 
is negative because the deceleration applied by the brakes.
In the other hand, the equation that describes the distance in term of velocities and acceleration:
, where 
is the distance traveled, is the initial velocity, the time of the process and, is the acceleration of the process.
Then for this case the relationship becomes: 
.
<u>Note that the acceleration is negative because is a braking process.</u>
We Know,
K.E. = 1/2 mv²
480 = 1/2 (m)(8)²
m = 960/64
m = 15 Kg
So, the mass of the object is 15 Kg
Answer:
The neutral state of an atom is when it's net charge is zero; that is, the number of protons equals the numbers of electrons. Oxygen is the eighth element in the periodic table, with the symbol O. This means that it has eight electrons in its neutral state. Since it is neutral, it also has eight protons!
Answer:
a) 
b) 
c) 
d) 
Explanation:
Given:
mass of the player, 
mass of the ball, 
initial velocity of the player, 
initial velocity of the ball, 
a)
<u>Case:</u> When the player and the ball are moving in the same direction.
where:
total mass after the player catches the ball
v = final velocity of the system
b)
Initial kinetic energy of the system:
![KE_i=\frac{1}{2} [m_p.v_p^2+m_b.v_b^2]](https://tex.z-dn.net/?f=KE_i%3D%5Cfrac%7B1%7D%7B2%7D%20%5Bm_p.v_p%5E2%2Bm_b.v_b%5E2%5D)
![KE_i=\frac{1}{2} [102.5\times 8.5^2+0.47\times 22.5^2]](https://tex.z-dn.net/?f=KE_i%3D%5Cfrac%7B1%7D%7B2%7D%20%5B102.5%5Ctimes%208.5%5E2%2B0.47%5Ctimes%2022.5%5E2%5D)
Final kinetic energy of the system:
∴Change in kinetic energy
c)
<u>Case:</u> When the player and the ball are moving in the opposite direction.
d)
Final kinetic energy in this case:
∴Change in kinetic energy:
