Answer:
Lindsey biked 45 miles for 3 hours at 15 mph and walked 8 miles for 2 hours at 4 mph.
Explanation:
Speed = distance/time
Let the distance that Lindsey biked through be x miles and the time it took her to bike through that distance be t hours
Then, the rest of the distance that she walked is (53 - x) miles
And the time she spent walking that distance = (5 - t) hours
Her biking speed = 15 mph = 15 miles/hour
Speed = distance/time
15 = x/t
x = 15 t (eqn 1)
Her walking speed = 4 mph = 4 miles/hour
4 = (53 - x)/(5 - t)
53 - x = 4 (5 - t)
53 - x = 20 - 4t (eqn 2)
Substitute for X in (eqn 2)
53 - 15t = 20 - 4t
15t - 4t = 53 - 20
11t = 33
t = 3 hours
x = 15t = 15 × 3 = 45 miles.
(53 - x) = 53 - 45 = 8 miles
(5 - t) = 5 - 3 = 2 hours
So, it becomes evident that Lindsey biked 45 miles for 3 hours at 15 mph and walked 8 miles for 2 hours at 4 mph.
The relevant equation to use here is:
y = v0 t + 0.5 g t^2
where y is the vertical distance, v0 is initial velocity =
0, t is time, g = 9.8 m/s^2
y = 0 + 0.5 * 9.8 * 3^2
<span>y = 44.1 meters</span>
Archaeological evidence shows that Egyptians worked together to build the pyramids. Remains of quarries and ancient tools suggest that large slabs were created from rock beds. The slabs were placed on sleds and pulled to the building site. To make this process easier, men most likely poured oil on the roadway. This process is depicted in tomb paintings that date back to 1900 BCE.
Answer:
true i think
Explanation:
The amplitude of a sound wave determines its loudness or volume. A larger amplitude means a louder sound, and a smaller amplitude means a softer sound. In Figure 10.2 sound C is louder than sound B. The vibration of a source sets the amplitude of a wave.
