Answer:
45 s
Explanation:
To find the time it takes to stop, we first find the deceleration, a of the car from
v² = u² + 2as and a = (v² - u²)/2s were v = final velocity of car = 0 mph = 0 m/s, u = initial velocity of car = 30 mph = 30 × 1609.34 ft ÷ 3600 s = 13.41 ft/s and s = distance = 300 ft. Substituting the values into a, we ave
a = (v² - u²)/2s = (0² - 13.41²)/2×300 = -0.3 ft/s²
We then find the time for this deceleration from v = u + at ⇒ t = (v - u)/a
t = (v - u)/a = (0 - 13.41 ft/s)/-0.3 ft/s² = - 13.41 ft/s/-0.3 ft/s² = 44.7 s ≅ 45 s
So it takes 45 seconds to stop.
Because sound waves don't travel through the vaccume of space. Hope this helped
Metals, Metalloids, and Nonmetals These elements can be classified as metals, nonmetals but metalloids ,Metals are good conductors of heat and electricity, and are malleable they can be hammered into sheets and (ductile- they can be drawn into wire.)
Answer:
50 lb
Explanation:
Force, F = 60 pounds
extension in the spring, x = 10 inch = 10 / 12 foot
Work, W = F x
W = 60 x 10 / 12 = 50 lb