When the ruler is broughı near the inetal knob, it repels electrons in the metal. Electrons move away froni the ruler and down the metal rod. The knob now has a positive charge. The thin pieces of metal foil at the bottom of the metal rod now have a negative charge.
Answer:
Wavelength = 736.67 nm
Explanation:
Given
Energy of the photon = 2.70 × 10⁻¹⁹ J
Considering:
where, h is Plank's constant having value as 6.63 x 10⁻³⁴ J.s
The relation between frequency and wavelength is shown below as:
c = frequency × Wavelength
Where, c is the speed of light having value = 3×10⁸ m/s
So, Frequency is:
Frequency = c / Wavelength
So, Formula for energy:
Energy = 2.70 × 10⁻¹⁹ J
c = 3×10⁸ m/s
h = 6.63 x 10⁻³⁴ J.s
Thus, applying in the formula:
Wavelength = 736.67 × 10⁻⁹ m
1 nm = 10⁻⁹ m
So,
<u>Wavelength = 736.67 nm</u>
First we have to calculate the time taken to travel the distance 30 m, is
.
Now from equation of motion,

Given,
.
As object starts from rest, so u = 0.
Substituting these values in above equation, we get
.
Thus, the acceleration is 
Answer: The coefficient of static friction is 3.85 and The coefficient of kinetic friction is 2.8
Explanation:
in the attachment
Answer:
a) v = 6.43 m/s
b) v = 15.8 m/s
Explanation:
Speed of car = 56 km/h
56 km/h = 14.4 m/s
Angle rain makes on the glass to the vertical = 66°
Thus knowing that the opposite side of the angle is the distance moved by the car, and the adjacent side is the distance traveled by the rain in the same time
both of which are directly proportional to their velocities
Then
tan(66°) = 14.44m/s ÷ x
or x = 14.44/tan(66°)
Which is the vertical raindrop velocity of the relative to earth
v = 6.43 m/s vertically towards earth
For v relative to the car is we have vector sum of both velocities
v = √(14.44^2 + 6.43^2) = 15.8 m/s which is the velocity relative to car
= 15.8 m/s