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
<h2>
Answer: Infrared light</h2>
A dark nebula is a cloud of dust and cold gas, which does not emit visible light and hides the stars it contains.
These types of nebulae are composed mainly of the hydrogen they obtain from nearby stars, which is their fuel.
It is using infrared light that we can "observe" and analyze in detail what happens in the inner parts of these nebulae.
<em>"A concave lens is thinner at the center than it is at the edges."</em>
If this isn't on the list of choices, that's tough. We can't help you choose the best one if we don't know what any of them is.
Reflection from such a rough surface is called diffuse reflection and appears matte
