Dropped From a Truck
Q. A truck starts from restm/s, m/s and accelerates uniformly at 2.0 m/s²m/s². At t = 10 ss, a stone is dropped by a person standing on the top of the truckm/s² (6 mm high from the ground). Neglect air resistancem/s², , and take g as 10 m/s²m/s². What is the speed of the stone at t = 11 ss, in m/s?
Inputs
Outputs
speed?
How it's solved
Solved with MotionInAPlane
Given
- m/s²
- s
- m
- m/s²
- s
- m/s from “starts from rest”
- m/s from “starts from rest”
- m/s² from “standing on the top of the truck”
- m/s² from “Neglect air resistance”
- from “Neglect air resistance”
Find .
Working
- velocity after a time(carried, x)
- m/s
- time in parts(all along)
- s
- velocity after a time(falling, x)
- m/s
- velocity after a time(carried, y)
- m/s
- Neglect air resistance
- m/s²
- velocity after a time(falling, y)
- m/s
- magnitude from components(velocity of stone at later from ground)
- m/sto 3 significant figures
Conclusion
The stone leaves the truck with the truck's velocity and keeps it sideways, since nothing pushes it along any more, while gravity alone speeds it downward.
The web of concepts
given read from the words equation asked
The Ruby that solves it
The question and its solution are small Ruby files. The engine runs them.
1require_relative "../physics"23question :dropped_from_a_truck do4 kind :numerical5 describes "A truck starts from rest and accelerates uniformly at %{acceleration}. At t = %{dropped_at}, a stone is " \6 "dropped by a person standing on the top of the truck (%{height} high from the ground). Neglect air " \7 "resistance, and take g as %{gravity}. %{speed} at t = %{asked_at}, in m/s?"8 given acceleration: "2.0 m/s2"9 given dropped_at: "10 s"10 given height: "6 m"11 given gravity: "10 m/s2"12 given asked_at: "11 s"13 asks speed: "What is the speed of the stone"14end1require_relative "../questions/dropped_from_a_truck"2require_relative "../science/motion_in_a_plane/motion_in_a_plane"34solve :dropped_from_a_truck, using: MotionInAPlane do5 objects :stone6 axes :x, :y7 instants :start, :dropped, :later8 stone.goes(:carried, during: start..dropped)9 stone.goes(:falling, during: dropped..later)10 stone.goes(:all_along, during: start..later)1112 take acceleration: stone.acceleration(during: carried, along: x)13 take dropped_at: carried.time_taken14 take height: stone.position(at: dropped, along: y)15 take gravity: g16 take asked_at: all_along.time_taken1718 deduce_from "starts from rest", stone.velocity(at: start, along: x) => "0 m/s", stone.velocity(at: start, along: y) => "0 m/s"19 deduce_from "standing on the top of the truck", stone.acceleration(during: carried, along: y) => "0 m/s2"20 deduce_from "Neglect air resistance", stone.acceleration(during: falling, along: x) => "0 m/s2",21 stone.acceleration(during: falling, along: y) => -g2223 speed = stone.speed(at: later)24 answer speed:, in: "m/s", figures: 32526 conclusion "The stone leaves the truck with the truck's velocity and keeps it sideways, since nothing pushes " \27 "it along any more, while gravity alone speeds it downward."28endplayground.rb
1require_relative "../solutions/dropped_from_a_truck"23play_with :dropped_from_a_truck do4 title "Dropped From a Truck"5endThe laws it drew on
| quantity | written | units | within | from |
|---|---|---|---|---|
| volume | — | — | Vectors | |
| mass | — | — | Vectors | |
| speed | — | — | Vectors | |
| density | — | — | Vectors | |
| number of moles | — | — | Vectors | |
| angular frequency | — | — | Vectors | |
| work | — | — | Vectors | |
| current | — | — | Vectors | |
| temperature | — | — | Vectors | |
| pressure | — | — | Vectors | |
| time | s | 0 … 1e+05 | Vectors | |
| power | — | — | Vectors | |
| total path length | — | — | Vectors | |
| energy | — | — | Vectors | |
| gravitational potential | — | — | Vectors | |
| coefficient of friction | — | — | Vectors | |
| charge | — | — | Vectors | |
| acceleration | m/s² | — | Vectors | |
| velocity | m/s | — | Vectors | |
| displacement | m | — | Vectors | |
| angular velocity | — | — | Vectors | |
| force | — | — | Vectors | |
| angular momentum | — | — | Vectors | |
| linear momentum | — | — | Vectors | |
| electric field | — | — | Vectors | |
| average velocity | m/s | — | Vectors | |
| magnetic moment | — | — | Vectors | |
| relative velocity | — | — | Vectors | |
| impulse | — | — | Vectors | |
| first vector | — | 0 … ∞ | Vectors | |
| second vector | — | 0 … ∞ | Vectors | |
| angle between | — | 0 … 3.142 | Vectors | |
| resultant | — | 0 … ∞ | Vectors | |
| resultant direction | — | 0 … 3.142 | Vectors | |
| direction | — | -3.142 … 3.142 | Vectors | |
| x component | — | — | Vectors | |
| y component | — | — | Vectors | |
| position | m | — | Velocity | |
| path length | m | — | Velocity | |
| time taken | s | 0 … 1e+05 | Velocity | |
| average speed | m/s | — | Velocity | |
| starting position | m | — | Velocity | |
| final position | m | — | Velocity | |
| change of velocity | m/s | — | Acceleration | |
| average acceleration | m/s² | — | Acceleration | |
| starting velocity | m/s | — | Acceleration | |
| final velocity | m/s | — | Acceleration | |
| gravity | m/s² | — | UniformAcceleration | |
| displacement of stone during carried along x | m | — | ||
| position of stone at dropped along x | m | — | ||
| position of stone at start along x | m | — | ||
| displacement of stone during carried along y | m | — | ||
| position of stone at dropped along y | m | — | ||
| position of stone at start along y | m | — | ||
| displacement of stone during falling along x | m | — | ||
| position of stone at later along x | m | — | ||
| displacement of stone during falling along y | m | — | ||
| position of stone at later along y | m | — | ||
| displacement of stone during all along along x | m | — | ||
| displacement of stone during all along along y | m | — | ||
| average velocity of stone during carried along x | m/s | — | ||
| time taken of carried | s | 0 … 1e+05 | ||
| average velocity of stone during carried along y | m/s | — | ||
| average velocity of stone during falling along x | m/s | — | ||
| time taken of falling | s | 0 … 1e+05 | ||
| average velocity of stone during falling along y | m/s | — | ||
| average velocity of stone during all along along x | m/s | — | ||
| time taken of all along | s | 0 … 1e+05 | ||
| average velocity of stone during all along along y | m/s | — | ||
| average speed of stone during carried | m/s | — | ||
| path length of stone during carried | m | — | ||
| average speed of stone during falling | m/s | — | ||
| path length of stone during falling | m | — | ||
| average speed of stone during all along | m/s | — | ||
| path length of stone during all along | m | — | ||
| change of velocity of stone during carried along x | m/s | — | ||
| velocity of stone at dropped from ground along x | m/s | — | ||
| velocity of stone at start from ground along x | m/s | — | ||
| change of velocity of stone during carried along y | m/s | — | ||
| velocity of stone at dropped from ground along y | m/s | — | ||
| velocity of stone at start from ground along y | m/s | — | ||
| change of velocity of stone during falling along x | m/s | — | ||
| velocity of stone at later from ground along x | m/s | — | ||
| change of velocity of stone during falling along y | m/s | — | ||
| velocity of stone at later from ground along y | m/s | — | ||
| change of velocity of stone during all along along x | m/s | — | ||
| change of velocity of stone during all along along y | m/s | — | ||
| average acceleration of stone during carried along x | m/s² | — | ||
| average acceleration of stone during carried along y | m/s² | — | ||
| average acceleration of stone during falling along x | m/s² | — | ||
| average acceleration of stone during falling along y | m/s² | — | ||
| average acceleration of stone during all along along x | m/s² | — | ||
| average acceleration of stone during all along along y | m/s² | — | ||
| acceleration of stone during carried along x | m/s² | — | ||
| acceleration of stone during carried along y | m/s² | — | ||
| acceleration of stone during falling along x | m/s² | — | ||
| acceleration of stone during falling along y | m/s² | — | ||
| acceleration of stone during all along along x | m/s² | — | ||
| acceleration of stone during all along along y | m/s² | — | ||
| acceleration of stone during carried | m/s² | — | ||
| acceleration of stone during all along | m/s² | — | ||
| acceleration of stone during falling | m/s² | — | ||
| velocity of ground at start from ground along x | m/s | — | ||
| velocity of ground at start from ground | m/s | — | ||
| direction of ground at start from ground | — | -3.142 … 3.142 | ||
| velocity of ground at start from ground along y | m/s | — | ||
| velocity of ground at dropped from ground along x | m/s | — | ||
| velocity of ground at dropped from ground | m/s | — | ||
| direction of ground at dropped from ground | — | -3.142 … 3.142 | ||
| velocity of ground at dropped from ground along y | m/s | — | ||
| velocity of ground at later from ground along x | m/s | — | ||
| velocity of ground at later from ground | m/s | — | ||
| direction of ground at later from ground | — | -3.142 … 3.142 | ||
| velocity of ground at later from ground along y | m/s | — | ||
| velocity of stone at start from ground | m/s | — | ||
| direction of stone at start from ground | — | -3.142 … 3.142 | ||
| velocity of stone at dropped from ground | m/s | — | ||
| direction of stone at dropped from ground | — | -3.142 … 3.142 | ||
| velocity of stone at later from ground | m/s | — | ||
| direction of stone at later from ground | — | -3.142 … 3.142 | ||
| displacement of stone during carried | m | — | ||
| position of stone at dropped | m | — | ||
| position of stone at start | m | — | ||
| displacement of stone during falling | m | — | ||
| position of stone at later | m | — | ||
| displacement of stone during all along | m | — | ||
| average velocity of stone during carried | m/s | — | ||
| average velocity of stone during falling | m/s | — | ||
| average velocity of stone during all along | m/s | — | ||
| change of velocity of stone during carried | m/s | — | ||
| change of velocity of stone during falling | m/s | — | ||
| change of velocity of stone during all along | m/s | — | ||
| average acceleration of stone during carried | m/s² | — | ||
| average acceleration of stone during falling | m/s² | — | ||
| average acceleration of stone during all along | m/s² | — |