The train accelerates at the rate of 20 for some time, until it's just exactly
time to put on the brakes, decelerate at the rate of 100, and come to a
screeching stop after a total distance of exactly 2.7 km.
The speed it reaches while accelerating is exactly the speed it starts decelerating from.
Speed reached while accelerating = (acceleration-1) (Time-1) = .2 time-1
Speed started from to slow down = (acceleration-2) (Time-2) = 1 time-2
The speeds are equal.
.2 time-1 = 1 time-2
time-1 = 5 x time-2
It spends 5 times as long speeding up as it spends slowing down.
The distance it covers speeding up = 1/2 A (5T)-squared
= 0.1 x 25 T-squared = 2.5 T-squared.
The distance it covers slowing down = 1/2 A (T-squared)
= 0.5 T-squared.
Total distance = 2,700 meters.
(2.5 + .5) T-squared = 2,700
T-squared = 2700/3 = 900
T = 30 seconds
The train speeds up for 150 seconds, reaching a speed of 30 meters per sec
and covering 2,250 meters.
It then slows down for 30 seconds, covering 450 meters.
Total time = <u>180 sec</u> = 3 minutes, minimum.
Observation:
This solution is worth more than 5 points.
Answer:
The answer to your question is 6 km/s
Explanation:
Acceleration is a change in velocity with respect to time, its units are m/s² or km/h².
Data
vo = 15 km/h
vf = 45 km/h
t = 5 s
Formula
Substitution
a = (45 - 15) / 5
a = 30 / 5
a = 6 km/s
Answer:
The second system must be set in motion seconds later
Explanation:
The oscillation time, T, for a mass, m, attached to spring with Hooke's constant, k, is:
One oscillation takes T secondes, and that is equivalent to a 2π phase. Then, a difference phase of π/2=2π/4, is equivalent to a time t=T/4.
If the phase difference π/2 of the second system relative to the first oscillator. The second system must be set in motion seconds later
Answer:
- Satelites that collect information about the rover vehicle
- Distance space stations that store real-time data about the rover vehicle
- Doppler radar that records information about weather the rover is exposed to.
Explanation:
The first rover that landed on Mars was the Mars pathfinder (Sojourner) that landed on the 4th of July 1997.In total NASA has sent four rover to Mars.These are
- Sojourner
- Spirit
- Opportunity
- Curiosity