Answer:
0.714 m
Explanation:
From the question,
v = λf......................... Equation 1
Where v = velocity of visible light, f = frequency of visible light, λ = wave length of visible light.
make λ the subject of the equation
λ = v/f.................. Equation 2
Given: f = 4.2×10⁸ Hz
Note: Light is an electromagnetic wave, and all electromagnetic waves travels with the same speed (3×10⁸ m/s)
Constant: v = 3×10⁸ m/s
Substitute these values into equation 2
λ = 3×10⁸/4.2×10⁸
λ = 0.714 m
Answer:
Explanation:
We shall represent the velocity of cruise ship and coast guard petrol boat in vector form .
velocity of cruise ship
Vcs = - 2.5 j
Vpb = - 4.8 cos 19 i + 4.8 sin 19 j = - 4.54 i + 1.56 j
velocity of the cruise ship relative to the patrol boat
= Vcs - Vpb
= - 2.5 j - ( - 4.54 i + 1.56 j )
= - 2.5 j + 4.54 i - 1.56 j
= 2.04 i - 1.56 j .
x-component of the velocity of the cruise ship relative to the patrol boat
= 2.04 m /s
y-component of the velocity of the cruise ship relative to the patrol boat
= - 1.56 m /s .
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:
It depends on where the temperature is dropping, in which body so to speak. Generally, the temperature adapts to the two bodies, for example if a hot piece of metal meets a cold one, the two will continue until they are at an equal temperature, an intermediate temperature.
Answer:
350 N/m
Explanation:
If we are assuming the stretch does not exceed the elastic range of the material, then by Hooke's law the spring constant of the cord is simply the ratio between the force 70N acting on the cord to stretch 20cm or 0.2m
k = 70 / 0.2 = 350 N/m
The spring constant is 350 N/m
