Answer:
a=1.024m/s
t=15.62s
Explanation:
A body that moves with constant acceleration means that it moves in "a uniformly accelerated movement", which means that if the velocity is plotted with respect to time we will find a line and its slope will be the value of the acceleration, it determines how much it changes the speed with respect to time.
When performing a mathematical demonstration, it is found that the equations that define this movement are as follows.
Vf=Vo+a.t (1)
{Vf^{2}-Vo^2}/{2.a} =X (2)
X=Xo+ VoT+0.5at^{2} (3)
X=(Vf+Vo)T/2 (4)
Where
Vf = final speed
Vo = Initial speed
T = time
A = acceleration
X = displacement
In conclusion to solve any problem related to a body that moves with constant acceleration we use the 4 above equations and use algebra to solve
for this problem
Vf=16m/s
Vo=0m/s, the cart starts from the rest
X=125m
we can use the ecuation number tow to calculate the acceleration
{Vf^{2}-Vo^2}/{2.a} =X
{Vf^{2}-Vo^2}/{2.x} =a
{16^{2}-0^2}/{2(125)} =a
a=1.024m/s
to calculate the time we can use the ecuation number 1
Vf=Vo+a.t
t=(Vf-Vo)/a
t=(16-0)/1.024
t=15.62s
Answer:
a. chemical contamination of streams ans rivers
d. adaptation
Answer:
AB = 29
Explanation:
For a better understanding, we must work this problem in a graphic way. In the attached image we can see the solution.
First, we draw a vertical dotted lines from the point J & K to the line ML, then we can see two new portions with the same length. Then with this simple analysis:
2x = 39 - 19
x = 10
Then we know that x = 10, another important data to find the answer is that the AB line is located in the midpoints of the legs. We also can see the right triangle MJ and the dotted line.
Now for every single right triangle, no matter its size and relationship between the vertical and the horizontal lengths, if some point is located in the hypotenuse (leg) at the middle of its length. This will be proportional to the vertical and the horizontal cathetus, therefore we will have the middle point on those two lines.
So, the AB line will be the sum of JK plus two times 5
AB = 19 + 5 + 5 = 29
Answer:
0.694 m
Explanation:
Case 1 : When only mass of 2.82 kg is hanged from spring
m = mass hanged from the spring = 2.82 kg
x = stretch caused in the spring = 0.331 m
k = spring constant
Using equilibrium of force in vertical direction
Spring force = weight of the mass
k x = m g
k (0.331) = (2.82) (9.8)
k = 83.5 N/m
Case 2 : When both masses are hanged from spring
m = mass hanged from the spring = 3.09 + 2.82 = 5.91 kg
x = stretch caused in the spring = ?
k = spring constant = 83.5 N/m
Using equilibrium of force in vertical direction
Spring force = weight of the mass
k x = m g
(83.5) x = (5.91) (9.8)
x = 0.694 m
