Answer:
Given the area A of a flat surface and the magnetic flux through the surface 
it is possible to calculate the magnitude 
.
Explanation:
The magnetic flux gives an idea of how many magnetic field lines are passing through a surface. The SI unit of the magnetic flux is the weber (Wb), of the magnetic field B is the tesla (T) and of the area A is (
). So 1 Wb=1 T.m².
For a flat surface S of area A in a uniform magnetic field B, with 
being the angle between the vector normal to the surface S and the direction of the magnetic field B, we define the magnetic flux through the surface as:
We are told the values of and B, then we can calculate the magnitude
Answer:
Speed of the boat, v = 4.31 m/s
Explanation:
Given that,
Height of the bridge, h = 32 m
The model boat is 11 m from the point of impact when the key was released, d = 11 m
Firstly, we will find the time needed for the boat to get in this position using second equation of motion as :
Here, u = 0 and a = g
t = 2.55 seconds
Let v is the speed of the boat. It can be calculated as :
v = 4.31 m/s
So, the speed of the boat is 4.31 m/s. Hence, this is the required solution.
The object takes 0.5 seconds to complete one rotation, so its rotational speed is 1/0.5 rot/s = 2 rot/s.
Convert this to linear speed; for each rotation, the object travels a distance equal to the circumference of its path, or 2<em>π</em> (1.2 m) = 2.4<em>π</em> m ≈ 7.5 m, so that
2 rot/s = (2 rot/s) • (2.4<em>π</em> m/rot) = 4.8<em>π</em> m/s ≈ 15 m/s
thus giving it a centripetal acceleration of
<em>a</em> = (4.8<em>π</em> m/s)² / (1.2 m) ≈ 190 m/s².
Then the tension in the rope is
<em>T</em> = (50 kg) <em>a</em> ≈ 9500 N.
Yes!
I think there are two ways you could go with this answer:
1) Acceleration is the change in velocity over time, it can be negative or positive. If you have an object that is already moving forwards in a straight line and give it a constant negative acceleration, it will slow down and then start going in reverse.
2)Velocity is a vector, meaning it has both magnitude and direction. In the example above, the acceleration is due to a change in magnitude, or speed (from +ve to -ve) but not a change in direction. Something that has constant speed but is changing direction is also accelerating (like something that is orbiting). You could use the earth as an example, which is constantly accelerating due to moving in a circle around the sun. At any time in the year you can say that in half a year's time the earth's direction will be reversed.
