Answer:
The required net force has a magnitude of 7200 N
Explanation:
Use Newton's 2nd Law to obtain the answer:

Answer:

Explanation:
The cabinet does not move: this means that the net force acting on it is zero.
Along the horizontal direction, we have two forces:
- The push exerted by Bob, F = 200 N, forward
- The frictional force,
, which acts in the opposite direction (backward)
Since the net force must be zero, we have:

So solving the equation we can find the magnitude of the friction force:

Answer:
e = 1.21 mV
Explanation:
given,
length of rod = 10 m
height of drop = 4.89 m
Earth’s magnetic field = 12.4 µT
acceleration of gravity = 9.8 m/s²
velocity of the beam


v = 9.79 m/s
emf of the beam
e = B l v
e = 12.4 x 10⁻⁶ x 9.79 x 10
e = 1.21 x 10⁻³ V
e = 1.21 mV
Active Optics.
Hope that helps, Good luck! (:
Total energy will remain the same