Answer:
The car will travel 30 miles during the 30-minutes period of acceleration.
Explanation:
Given data :
Initial velocity = v₁ = 50 miles/hour
Final velocity = v₂ = 70 miles/hour
Time = t = 30 min = 0.5 hour
Using the definition of acceleration, we find the acceleration (a)
a = (v₂ - v₁) ÷ t
a = (70 - 50) ÷ 0.5
a = 20 ÷ 0.5
a = 40 miles/hour²
Using 3rd equation of motion, we find the distance travel (s)
2as = v₂² - v₁²
2(40)s = 70² - 50²
80 × s = 4900 - 2500
s = 2400 ÷ 80
s = 30 miles
Letter B
without a medium, there is nothing to compress, hence, no wave. A fast- medium like a gas (air) is easy to compress and allows waves to move through it easily. a slow medium, like a liquid, is still pretty fast, but not as fast as air.
ripples on the surface of water.
vibrations in a guitar string.
a Mexican wave in a sports stadium.
electromagnetic waves – eg light waves, microwaves, radio waves.
seismic S-waves.
Fk = μK N
N = m a
N = 4 × a
N = 4a
Fk = μK N
17 = 5 × 4a
17 = 20 a
a = ¹⁷/₂₀ = 0.85 m/s²
