Answer:
The answer to your question is: vo = 25 m/s
Explanation:
data
a = -7.5 m/s²
d = 42 m
vf = 0 m/s
vo = ?
Formula
vf² = vo² - 2ad
Substitution
0² = vo² - 2(7.5)(42)
We clear vo from the equation
vo² = 2(7.5)(42)
vo² = 630 simplifying
vo = 25 m/s result
A car moves along an x axis through a distance of 900 m, starting at rest (at x = 0) and ending at rest (at x = 900 m). Through the first 1/4 of that distance, its acceleration is +6.25 m/s2. Through the next 3/4 of that distance, its acceleration is -2.08 m/s2. What are (a) its travel time through the 900 m and (b) its maximum speed?
<span>Solve for the time at the 1/4 mark. That's 225 m. How? d = (1/2)at^2 ( initial velocity zero). Thus 225 = (1/2) 6.25 t^2. t^2 = ( 225 * 2 ) / 6.25. t = 8.5 sec. </span>
<span>At the other end t^2 = (675 * 2) / 2.08 -- we reversed the sign and ran time backwards. t = 25.5 sec. </span>
<span>So total time is 8.5 + 25.5 or 34 sec. </span>
<span>Since zero initial velocity: v^2 = 2 a d. Here, v^2 = 2 * 6.25 * 225. v = 53 m/s. That's the fastest speed since braking then occurs.</span>
An object can be at rest and still be in motion because the earth is always in motion.
Answer:
138.18 minutes
Explanation:
= Latent heat of water at 0°C = 80 cal/g
m = Mass of water = 570 g
Heat removed for freezing
Let N be the number of cycles and each cycle removes 56 cal from the freezer.
So,
Each cycle takes 10 seconds so the total time would be
The total time taken to freeze 138.18 minutes
This is because in 1918 there was a law created to save birds. It was the Migratory Bird Treaty act
