The same thing that holds everything else 'down' --- gravity.
Answer:
Explanation:
Speed of electron
v = 4 × 10^5 •j m/s
Magnetic field
B = 5 × 10^-5 T at angle of 45° to horizontal
Charge of electron
q = 1.6 × 10^-19C
Magnitude of force F?
The Force exerted in an electric field is given as
F = q(v×B)
Now, x component of the magnetic field
Bx = BCos45 = 5×10^-5 Cos45
Bx = 3.54 × 10^-5 •i T
Also, y component
By = BSin45 = 5 × 10^-5Sin45
By = 3.54 × 10^-5 •j T
B = 3.54 × 10^-5 •i + 3.54 × 10^-5 •j T
Now, F = q(v×B)
Note that,
i×i=j×j=k×k=0
i×j =k, j×k = i, k×i = j
j×i = -k, k×j = -i and i×k = -j
Therefore
F = q(v×B)
F = 1.6×10^-19(4×10^5•j × (3.54 × 10^-5 •i + 3.54 × 10^-5 •j T))
F = 1.6×10^-19 (4×10^5 × 3.54 × 10^-5 (j×i) + 4×10^5 × 3.54 × 10^-5(j×j))
F = 1.6×10^-19(14.14(-k) + 0)
F = —2.26 × 10^-18 •k N
It is in the negative direction of z axis
The magnitude of the force the field experience is 2.26 × 10^-18 N
Number a is a correct one
Answer:
Acceleration.
Explanation:
In physics, acceleration can be defined as the rate of change of the velocity of an object with respect to time.
This simply means that, acceleration is given by the subtraction of initial velocity from the final velocity all over time.
Hence, if we subtract the initial velocity from the final velocity and divide that by the time, we can calculate an object’s acceleration.
Mathematically, acceleration is given by the equation;
Where,
a is acceleration measured in
v and u is final and initial velocity respectively, measured in
t is time measured in seconds.
Hence, in a velocity-time graph, acceleration is represented by the slope, or steepness, of the graph line.
Bcoz when you place a magnet close enough the magnet attracts or repals without any other fore we dont touch the magnet so it is non contact