Answer:
1. 3 m
2. 27 s
Explanation:
1. "A car traveling at +33 m/s sees a red light and has to stop. If the driver can accelerate at -5.5 m/s², how far does it travel?"
Given:
v₀ = 33 m/s
v = 0 m/s
a = -5.5 m/s²
Unknown: Δx
To determine the equation you need, look for which variable you don't have and aren't solving for. In this case, we aren't given time and aren't solving for time. So look for an equation that doesn't have t in it.
Equation: v² = v₀² + 2aΔx
Substitute and solve:
(0 m/s)² = (33 m/s)² + 2(-5.5 m/s²) Δx
Δx = 3 m
2. "A plane starting from rest at one end of a runway accelerates at 4.8 m/s² for 1800 m. How long did it take to accelerate?"
Given:
v₀ = 0 m/s
a = 4.8 m/s²
Δx = 1800 m
Unknown: t
Equation: Δx = v₀ t + ½ a t²
Substitute and solve:
1800 m = (0 m/s) t + ½ (4.8 m/s²) t²
t ≈ 27 s
Answer:
B= 55.6×10^(-7) Tesla
Explanation:
B= μoI/(2πr)
B: magnetic field strength
μo: permeability of free space and is equal to 4π×10^(-7) T.m/A
r: distance from the wire
I : current in the wire
B= (4π×10^(-7)×125)/(2π×4.5)
B= 55.6×10^(-7) Tesla
Answer:
0.0667 m
Explanation:
λ = wavelength of light = 400 nm = 400 x 10⁻⁹ m
D = screen distance = 2.5 m
d = slit width = 15 x 10⁻⁶ m
n = order = 1
θ = angle = ?
Using the equation
d Sinθ = n λ
(15 x 10⁻⁶) Sinθ = (1) (400 x 10⁻⁹)
Sinθ = 26.67 x 10⁻³
y = position of first minimum
Using the equation for small angles
tanθ = Sinθ = y/D
26.67 x 10⁻³ = y/2.5
y = 0.0667 m
