Answer:
Highest point reached = 3.37 m
Explanation:
Initial velocity, = 7.1 m/s
Initial vertical velocity = 7.1 sin 61 = 6.21 m/s
Consider the vertical motion of skateboarder,
We have equation of motion, v² = u² + 2as
Initial velocity, u = 6.21 m/s
Acceleration, a = -9.81 m/s²
Final velocity, v = 0 m/s
Substituting
v² = u² + 2as
0² = 6.21² + 2 x -9.81 x s
s = 1.97 m
So from ramp the position it goes up by 1.97 m
Highest point reached = 1.97 + 1.4 = 3.37 m
Do you remember this formula for the distance traveled while accelerated ?
<u>Distance = (initial speed) x (t) plus (1/2) x (acceleration) x (t²)</u>
I think this is exactly what we need for this problem.
initial speed = 20 m/s down
acceleration = 9.81 m/s² down
t = 3.0 seconds
Distance down = (20) x (3) plus (1/2) x (9.81) x (3)²
Distance = (60) plus (4.905) x (9)
Distance = (60) plus (44.145) = 104.145 meters
Choice <em>D)</em> is the closest one.
From the given problem, a limit on the depression of a building is placed at 20 centimeters. To solve how many floors can be safely added, a quantity of how many cm will a building sink for each floor that is added is needed. Unfortunately, it is not found anywhere in the problem. However, we can provide a formula to solve for the depression. This is as follows:
Building depression < 20 cm
Building depression = (cm depression per floor) * (no. of floors)
I can't see numbers here, so here are all the answers:
1) the frequency is c/λ = 3e8/556e-9 = 5.39e14Hz
2) light travels at <span>299,792,458 m/s. So in nanoseconds it's 0.299792458m. This is about 1/3 of a meter which is about one foot.
3) length is L = ct = (</span>299,792,458 m/s)(6e-15) = 1.799e-6m or 1.799μm
Answer:
The charge density in the system is 
Explanation:
To solve this problem it is necessary to keep in mind the concepts related to current and voltage through the density of electrons in a given area, considering their respective charge.
Our data given correspond to:
We need to asume here the number of free electrons in a copper conductor, at which is generally of 
The equation to find the current is
Where
I =Current
V=Velocity
A = Cross-Section Area
e= Charge for a electron
n= Number of free electrons
Then replacing,
Now to find the linear charge density, we know that
Where:
I: current intensity
Q: total electric charges
t: time in which electrical charges circulate through the conductor
And also that the velocity is given in proportion with length and time,
The charge density is defined as
Replacing our values
Therefore the charge density in the system is
