knowledge of first aid ... eg St John Ambulance, Red Cross etc. I think that everyone in a school should be taught First Aid.
Answer: the magnetic wave will travel out of the screen.
Explanation:
Electric field direction is perpendicular to the magnetic field direction. Both are also perpendicular to the direction of the particles.
Using right hand rule to solve this problem,
This pointed finger depicts the electric field direction which the curly fingers depict the direction of the magnetic field. The pointed thumb will depict the direction in which the wave travel. Which is out of the screen.
Answer: The pressure exerted on a surface by an object increases as the surface area of contact decreases.
Explanation:
Pressure measures the amount of force exerted per a given area of an object. From this definition, the surface area of the object and force applied, affects the pressure applied.
As Benny presses his finger against a map, nothing happens to the map because the force applied is affected by the increased surface area of his finger. However as he presses a thumbtack into the map using the same force the tack will probably poke a hole in the map because the small( decreased) surface area of the sharp point of the thumbtack produces a much larger pressure on the map than the area of Benny finger. I hope this helps, thanks!
Acceleration = (change in velocity) / (time for the change)
Change in velocity = 59.43 m/s East
Time for the change = 0.312 s
Acceleration = 190.5 m/s^2 East
Answer:
a. 192 m/s
b. -17,760 kPa
Explanation:
First let's write the flow rate of the liquid, using the following equation:
Q = A*v
Where Q is the flow rate, A is the cross section area of the pipe (A = pi * radius^2) and v is the speed of the liquid. The flow rate in both parts of the pipe (larger radius and smaller radius) needs to be the same, so we have:
a.
A1*v1 = A2*v2
pi * 0.02^2 * 12 = pi * 0.005^2 * v2
v2 = 0.02^2 * 12 / 0.005^2
v2 = 192 m/s
b.
To find the pressure of the other side, we need to use the Bernoulli equation: (600 kPa = 600000 N/m2)
P1 + d1*v1^2/2 = P2 + d1*v2^2/2
Where d1 is the density of the liquid (for water, we have d1 = 1000 kg/m3)
600000 + 1000*12^2/2 = P2 + 1000*192^2/2
P2 = 600000 + 72000 - 1000*192^2/2
P2 = -17760000 N/m2 = -17,760 kPa
The speed in the smaller part of the pipe is too high, the negative pressure in the second part means that the inicial pressure is not enough to maintain this output speed.
