Answer:
The answer is D.
Explanation:
A truck is traveling at a constant speed of 20 m/s through a school zone. At time t = 0 seconds, he passes a hidden police car that is at rest. Five seconds after the truck passes, the police car begins accelerating at a constant rate of 2 m/s in order to catch the truck.
Determine the time at which the speed of the truck is equal to the speed of the police car. Mark this time as t↓1. How will the positions of the police car and the truck compare when they have the same speed and why?
Answer:
Let's define:
The position zero will be in the first point where the truck and police car meet. (So the initial position of both vehicles is zero)
Then, the position equation for the truck is:
T(t) = 20m/s*t
Where t is our variable, time in seconds.
Now, at t = 5s, the car starts accelerating.
Ac(t) = 2m/s^2 for( t ≥ 5s)
For the velocity of the car, we must integrate that.
V(t) = (2m/s^2)*(t - 5) for (t ≥ 5s)
Where i introduced a little change in the variable because the velocity of the car starts to increase for t larger than 5 seconds.
For the position of the car we integrate again.
C(t) = (1m/s)*(t - 5)^2 for (t ≥ 5s)
Now, let's answer the questions:
Determine the time at which the speed of the truck is equal to the speed of the police car.
Then we must have:
V(t) = (2m/s^2)*(t - 5) = 20m/s. (Remember that we only can use times requal or larger than 5 seconds).
2m/s^2*t - 10m/s = 20m/s
2m/s^2*t = 30m/s
t = (30/2) s = 15s
The velocities of both vehicles will be the same after 15 seconds.
t1 = 15s
How the positions will compare at this time?
The easier thing will be to evaluate the position equation of each vehicle in this time:
T(15s) = 20m/s*15s = 300m
C(15s) = (1m/s^2)*(15s - 5s)^2 = (1m/s^2)*(10s)^2 = 100m.
Then we can see that the truck is 200m ahead of the car.
But remember that the police car is accelerating, so the velocity will keep increasing meaning that eventually, the car will catch the truck.
what is one second time ?
Answer:
one second is defined au1/86400th the part of a solar day
is isopropyl alcohol a element compound or mixture
Answer:
Isopropyl is an element compound.
Explanation:
Look at pic.... 2 examples of radiation and how they are radiation
Answer:21
Explanation:
velocity is derived physical quantity why
Answer:
Velocity is “how much distance you cover in a particular time.” Space and time are fundamental quantities, and meters and seconds are their base units. Velocity is a combination of a space and a time, and therefore its units — “m/s” – are “derived” from the units for space and time
whats the order of solid liquid and gas from least particle motion to the most?
Answer:
Solid < Liquid < Gas
In which box could “gas” be placed?
*C. W is not the answer
в горизонтальном положении бревно длиной 18 м можно уравновесить на подставке, отстоящей на 3 м от его толстого конца. Если же подставка находится в 6 м от толстого конца, и на тонкий конец сядет рабочий массой 60 кг, то бревно снова будет в равновесии. Определите массу бревна.
Ответ:
90кг
Пояснение:
Найдите эскиз прилагаемой схемы. Масса бревна M размещается на отметке 3 см от толстого конца, а стержень размещается на отметке 6 см от массы бревна.
Согласно принципу момента, сумма момента по часовой стрелке равна сумме момента против часовой стрелки.
Вес корпуса в более тонкой части W = мг
W = 60 × 10 = 600 Н
Момент по часовой стрелке = 600 × 9
CW момент = 5400 Нм
Момент против часовой стрелки = M × 6
Момент ACW = 6M
Уравнять оба момента
6M = 5400
М = 5400/6
М = 900Н
Масса бревна = 900/10
Масса бревна = 90кг
A 15-N force and a 45-N force act on an object in opposite directions
What is the net force on the object? *
Answer:
30-N
Explanation:
Because they are both acting on an object going opposite directions, then you simply subtract the 15 from 45 as 45N of force is stronger than 15N of force.
The net force on the object is 30 Newton due to these two opposite forces.
What is force?The definition of force in physics is: The push or pull on a massed object changes its velocity. An external force is an agent that has the power to alter the resting or moving condition of a body. It has a direction and a magnitude.
A spring balance can be used to calculate the Force. The Newton is the SI unit of force.
Here, a 15-N force and a 45-N force act on an object in opposite directions.
The net force on the object due to these two opposite forces is = 45 N - 15 N
= 30 N.
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Which scenario does not describe an example of acceleration?
A car increases its speed while turning to the left.
A car decreases its speed while driving straight ahead.
A car maintains a constant speed while turning to the right.
A car maintains a constant speed while driving straight ahead.
Answer:
B is the right answer
Explanation:
It is decreasing.
A car maintains a constant speed while driving straight ahead.
What is acceleration?The acceleration of an object is the rate of change of velocity with time. It is measured in meter per second square.
Velocity of the carThe car undergoes velocity when there is change in direction of the speed.
Thus, the only option that does not describe acceleration is a car maintains a constant speed while driving straight ahead.
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what would a boats velocity be if it would go 15kph and 18 kph?
Answer:
It depends
Explanation:
What is the kinetic Energy of the 80 kg skydiver if he is falling at 60 m/sec?
Answer:
144000J
Explanation:
Ek=1/2mv²
Ek=1/2×80×60²
Ek=144000J
what is the speed of sound in temperature of 56 degrees C?
Answer:
316 meters/second.......Answer:
316 meters/second
what are two different examples of positive exeleration
Answer:Accelerating your car to get up to speed on a freeway
An airplane accelerating to take off
Accelerating out of the starting blocks at a track meet
Explanation:
HELP GIVING BRAINLIEST
Answer:
16: x4
17 x2
18; 4.5 for q1 and 4.5 for q2
Explanation:
A 1500 kg car traveling at 15m/s to the south collides with a 4500 kg truck that is initially at rest at a stoplight. the car and truck stick together and move together after the collision, what is the final velocity of the two vehicles
Answer: 3.75 m/s
Explanation:
Here's what you know: The car has mass 1500 kg, and initial velocity 15.0 m/s. The truck has mass 4500 kg and initial velocity 0 m/s. The final mass is 6000 kg (4500 kg plus 1500 kg, because they stick together) and we are looking for the final velocity. Using the formula p = mv, and the concept that p before equals p after, the p of the car plus p of the truck equals the p of them together. So, 1500 x 15 + 4500 x 0 = 6000 x v final. 22500 = 6000 v, and v = 3.75 m/s. The velocity is positive, and the initial velocity of the car was positive, so the two vehicles together are traveling to the south just like the car was initially.
60 point!!!
Instructions-
Give a real life example of each of Newton's Laws in action. Be sure to specificy which law your
example is linked to.
Give examples with pulleys
Answer:
Playing hockey, driving a car, and even simply taking a walk are all everyday examples of Newton's laws of motion.
4. Calculate the momentum for each scenario:
a. .02 kg mass moving at 300 m/s
b. 2 kg mass moving at 40 m/s
c. 200 kg mass moving at 4 m/s
a) Answer:
Momentum = 6 kgm/s
Explanation:
Momentum = mass × velocity
Given that,
mass = 0.02 kg velocity = 300 m/s
Therefore, momentum = (0.02 × 300)kgm/s
Momentum = 6 kgm/s
b) Answer:
Momentum =80 kgm/s
Explanation:
Momentum = mass × velocity
Given that,
mass = 2 kg velocity = 40 m/s
Therefore, momentum = (40 × 2)kgm/s
Momentum = 80 kgm/s
c) Answer:
Momentum = 800 kgm/s
Explanation:
Momentum = mass × velocity
Given that,
mass = 200 kg velocity = 4 m/s
Therefore, momentum = (200 × 4)kgm/s
Momentum =800 kgm/s
what is the least efficient way to roast a marshmallow using heat transfer conduction, convection, or radiation?
Answer:
convection
Explanation:
The only way convection can only take place in liquids and gas.Since the marshmello is neither,convection is the least effective way
how does a distance-time graph show you which direction the runner is moving? Use your own words and science vocabulary.
Please help will give brainliest to whoever does a 4 setence answer
In a distance time graph, when the x and y values are positive (in first quadrant), the runner is moving forward.
While, if the distance value ( in the y axis) is negative, the runner is moving backwards ( towards the start) .
Hope it helps :)
A distance-time graph shows how far an object has travelled in a certain time. This is a simple line graph that plots observations by distance versus time.
The distance is transferred to the Y axis.
Time is plotted on the X-axis.
The distance-time graph when we study the motion of bodies. If you set the distance and time of the movement of the object and transfer the same data to a rectangular graph, you will get a distance-time graph corresponding to the movement of the object.
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What type of glass is heat resistant?
A.leaded glass
B.tinted glass
C.borosilicate glass
D.tempered glass
Answer:
D.
Explanation:
Tempered glass is the less expensive alternative, and is best for lower temperature applications. It can withstand constant temperatures of up to 470 degrees F. Tempered glass is regular glass that has been strengthened through a thermal or chemical treatment. Tempering not only strengthens the glass but also changes its breakage pattern, causing it to shatter into small pieces instead of large sharp angles, reducing the chance of injury. It is best used for applications where the fire will not be near the glass, as constant temperatures of 500 degrees or more will cause it to weaken and shatter.
Which is a physical property of matter that is always the same regardless of size or amount
Answer:
ntensive properties: A physical property that will be the same regardless of the amount of matter.
Explanation:
what is a unit of electrical flow called
Answer:
AMPERE - A unit of measure for the flow of current in a circuit. One ampere is the amount of current flow provided when one volt of electrical pressure is applied against one ohm of resistance. The ampere is used to measure electricity much as "gallons per minute" is used to measure water flow.
Explanation:
hope it helps
A unit of electrical flow is known as ampere
what should you do if the exercise schedule you make for yourself is not working out well by midweek
Answer:
I will find a solution.
Explanation:
i will figure out the problem,then solve it
5. Michael wanted to see what kitchen cleaner worked best for cleaning her counters. He used Lysol, Clorox, Pine-sol, and just water. For each cleaner, he put 5 milliliters of grape juice on the counter, sprayed the cleaner, and wiped it with one paper towel.
Answer:
Michael wanted to see what kitchen cleaner worked best for cleaning his counters. He used Lysol, Clorox, Pine-Sol, and water. For each cleaner, he used 5 milliliters of grape juice on the counter, sprayed the cleaner, and wiped it with one paper towel. Which of the following would be a constant?
answer choices:
-Lysol
-Cleaning products
-5 milliliters of grape juice
-Cleanest countertop recorded
5 milliliters of grape juice will be constant.
Explanation:
The different cleaning agents have different cleaning capabilities and some will require more of its quantity than others to clean the counter.
Secondly, only the grape juice has a measured amount of 5 milliliters
The sum of potential energy and kinetic energy is
Answer:
The total mechanical energy
Explanation:
M = Mass
V = Velocity
G = Gravity
H = Height
KE = 1/2mv²
PE = mgh
ME = KE + PE
ME = 1/2 mv² + mgh
What are some common measurements that are given as a rate?
Answer:
taco bell
Explanation:
define fundamental units
Answer:
one of a set of unrelated units of measurement, which are arbitrarily defined and from which other units are derived. For example, in the SI system the fundamental units are the meter, kilogram, and second.
Explanation:
The slope of a distance vs. time graph is a measurement called
A. displacement
B. speed
C. correlation
D. velocity
Answer:
B. speed
Explanation:
im not sure hahahaha
An apple is dropped from a 260m high building. How long will it take to hit the ground in
seconds)?
Answer:
7.28 s
Explanation:
s=-260
u=0
assume a=-9.81
t=?
s=1/2at^2 + ut
-260=1/2 (-9.81) t^2 +0t
t=7.28 s
The time taken for the apple to hit the ground from the high building is 7.28s.
Given the data in the question;
Before the apple was dropped, it was initially at rest, so
Initial velocity; [tex]u = 0 m/s[/tex]Distance or height from which it was dropped from; [tex]s = 260m[/tex]
To find the time it will take for the apple to hit the ground
We use the Second Equation of Motion:
[tex]s = u^2 + \frac{1}{2}at^2[/tex]
Where s is the distance or height from which it was dropped, u is its initial velocity, t is time and a is the acceleration due to gravity.
We know that earth's gravitational field or acceleration due to gravity; [tex]g = 9.8m/s^2[/tex]
Since the apple is falling, it under gravity; [tex]a = g = 9.8m/s^2[/tex]
We substitute our values into the equation and find t
[tex]260m = (0m/s)^2 + (\frac{1}{2} \ *\ 9.8m/s^2\ *\ t^2 )\\\\260m = 4.9m/s^2 \ * \ t^2\\\\t^2 = \frac{260m}{4.9m/s^2}\\\\t^2 = 53.06^2\\\\t = \sqrt{53.06s^2} \\\\t = 7.28s[/tex]
Therefore, the time taken for the apple to hit the ground from the high building is 7.28s
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