Answer:
(E) μs(mA +mB)g
Explanation:
We can apply for mB:
∑ Fx = mB*a (→)
⇒ Ffriction = mB*a ⇒ a = Ffriction / mB = μs*N / mB
⇒ a = μs*(mB*g) / mB ⇒ a = μs*g (acceleration of the system)
Now, for mA we have
∑ Fx = mA*a (→)
F - Ffriction = mA*a ⇒ F = mA*a + Ffriction
⇒ F = mA*(μs*g) + μs*(mB*g) ⇒ F = μs*g*(mA + mB)
We must know that the friction acts only between the two blocks
2213
just add with a calculator
Answer:
50m
Explanation:im just smart thank me later
8. In soft magnetic materials such as iron, what happens when an external magnetic field is removed?
a. The domain alignment persists.
b. The orientation of domains fluctuates.
c. The material becomes a hard magnetic material.
d. The orientation of domains changes, and the material returns to an unmagnetized state.
9. According to Lenz’s law, if the applied magnetic field changes,
a. the induced field attempts to keep the total field strength constant.
b. the induced field attempts to increase the total field strength.
c. the induced field attempts to decrease the total field strength.
d. the induced field attempts to oscillate about an equilibrium value.
10. The direction of the force on a current-carrying wire in an external magnetic field is
a. perpendicular to the current only.
b. perpendicular to the magnetic field only.
c. perpendicular to the current and to the magnetic field.
d. parallel to the current and to the magnetic field
Answer:
The maximum height the box will reach is 1.72 m
Explanation:
F = k·x
Where
F = Force of the spring
k = The spring constant = 300 N/m
x = Spring compression or stretch = 0.15 m
Therefore the force, F of the spring = 300 N/m×0.15 m = 45 N
Mass of box = 0.2 kg
Work, W, done by the spring =
and the kinetic energy gained by the box is given by KE = 
Since work done by the spring = kinetic energy gained by the box we have
=
therefore we have v =
=
=
= 5.81 m/s
Therefore the maximum height is given by
v² = 2·g·h or h =
=
= 1.72 m