Vi = vf + ( a.t)
0 m/s (rest) = 80 m/s + (a.20s.-1)
a.20.-1= -80, we check if this is true; = 0 m/s= 80 + -80 = 0 ITS TRUE.
so a.20.-1= -80, a= 80/20 , Answers a= 4 m/s
Answer: 17.68 s
Explanation:
This problem is a good example of Vertical motion, where the main equation for this situation is:
(1)
Where:
is the height of the ball when it hits the ground
is the initial height of the ball
is the initial velocity of the ball
is the time when the ball strikes the ground
is the acceleration due to gravity
Having this clear, let's find from (1):
(2)
Rewritting (2):
(3)
This is a quadratic equation (also called equation of the second degree) of the form 
, which can be solved with the following formula:
(4)
Where:
Substituting the known values:
(5)
Solving (5) we find the positive result is:
Answer:
Southern state and local elections in 1876 differed from those in previous years in that the election of 1876 was one of the closest races in American history. It tested the Constitution and resulted in a compromise that ended Reconstruction in America.
The election of 1876 between Rutherford B. Hayes and Democrat Samuel Tilden of New York was one of the most hostile, controversial campaigns in American history. The vote was 8-7 along party lines to award the disputed electoral college votes to Hayes, making him the winner.
Explanation:
The Compromise of 1876 is known for being the catalyst for the end of Reconstruction era, it was one of the most contentious and controversial presidential elections in American history.
Republican nominee Rutherford B. Hayes faced Democrat Samuel J. Tilden. After a controversial post-election process, He lost the popular vote to Democrat Samuel J. Tilden but he won an intensely disputed electoral college vote after a Congressional commission awarded him twenty contested electoral votes Hayes was declared the winner. The Hayes-Tilden Compromise is often seen as the final point that brought an end to Reconstruction, as it led to the removal of the US army from the South.
As Florida's Supreme Court had earlier declared a Democratic victory in the 1876 gubernatorial election, Democrats had been restored to power all across the South. The Compromise of 1876 effectively ended the Reconstruction era.
Southern Democrats' promised to protect civil and political rights of blacks as they were not kept, and to end of federal interference in southern affairs. This led to widespread disenfranchisement of blacks voters. Other factors that contributed to the end of Reconstruction were the Panic of 1873 and political corruption in the United States.
The Compromise of 1877 (the Great Betrayal) was an informal, unwritten deal, that settled the intensely disputed 1876 U.S. presidential election. It resulted in the United States federal government pulling the last troops out of the South, and formally ended the Reconstruction Era.
Answer:
9.6 Ns
Explanation:
Note: From newton's second law of motion,
Impulse = change in momentum
I = m(v-u).................. Equation 1
Where I = impulse, m = mass of the ball, v = final velocity, u = initial velocity.
Given: m = 2.4 kg, v = 2.5 m/s, u = -1.5 m/s (rebounds)
Substitute into equation 1
I = 2.4[2.5-(-1.5)]
I = 2.4(2.5+1.5)
I = 2.4(4)
I = 9.6 Ns
