STEP ONE:
Let you and your friend stand as far away as possible from a large reflecting wall and clap your hands rapidly at a regular rate.
STEP TWO:
Adjust this rate until each clap just coincides with the return of an echo of its predecessor, or until clap and echo are heard as equally spaced.
STEP THREE:
Use a stopwatch to find the time between claps, t. Make a rough measurement of distance to the wall, s. Thus the speed of sound, v = 2s/t
Answer:
The wavelength of sunlight that can cause this bond breakage is 242 nm
Explanation:
The minimum energy of the sunlight that'll break Oxygen-oxygen bond must match 495 KJ/mol
But 1 mole of any molecule contains 6.02 × 10²³ molecules/mol
Each molecule of Oxygen will require (495 × 10³)/(6.02 × 10²³) = 8.22 × 10⁻¹⁹ J
E = hf
v = fλ
f = v/λ
f = frequency of the sunlight
λ = wavelength of the sunlight
v = speed of light = 3.0 × 10⁸ m/s
E = hv/λ
λ = hv/E
h = Planck's constant = 6.63 × 10⁻³⁴ J.s
λ = (6.63 × 10⁻³⁴)(3 × 10⁸)/(8.22 × 10⁻¹⁹)
λ = 2.42 × 10⁻⁷ m = 242 nm.
Answer: option D) 42.4 N
The weight of the frame is balanced by the vertical component of tension.
W = T sin θ + T sin θ = 2 T sin θ
The tension in each cable is T = 30 N
Angle made by the cables with the horizontal, θ = 45°
⇒ W = 2×30 N × sin 45° = 2 × 30 N × 0.707 = 42.4 N
Hence, the weight of the frame is 42.4 N. Correct option is D.
Power dissipation = (voltage across the component)² / (resistance of the component)
Since the resistance is in the denominator of the fraction in this formula for the
quantity of power dissipated, you can see that when the supply voltage is constant,
the smaller resistance dissipates more power.
So the <u>60w bulb</u> has lower resistance than the 40w bulb.
Rubber. The other three are metals, and therefore good conductors.
