Answer:
A. Speed
Explanation:
Speed is the magnitude of velocity, which is given in the question. Velocity is a vector quantity and therefore has both a magnitude and a direction. Only the former is implied in the question.
Answer:
B = 0.129 T
Explanation:
Given,
frequency, f = 60 Hz
maximum emf = 5200 V
Number of turns, N = 130
Area per turn = 0.82 m²
We know,
ω = 2 π f
ω = 2 π x 60 = 376.99 rad/s
now, Magnetic field calculation


B = 0.129 T
Hence, the magnetic field is equal to B = 0.129 T
Answer:
20min = 20 × 60 = 1200sec.
Speed in m per sec.
V = 1000/1200
V = 0.833m per sec.
Explanation:
Answer:
49 N
Explanation:
In order to move the box at constant speed, the acceleration of the box must be zero (a=0): this means, according to Newton's second law,
F = ma
that the net force acting on the box, F, must be zero as well.
Here there are two forces acting on the box in the horizontal direction while it is moving:
- The force of push applied by the guy, F
- The frictional force, 
For an object moving on a flat surface, the frictional force is given by

where
is the coefficient of friction
m is the mass of the box
g is the acceleration of gravity
So the equation of the forces becomes

And substituting:

We find the force that must be applied by the guy:
