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3 years ago

You’re speeding at 85 km/hr when you notice that you’re only 10 m behind the car in front of you,

1 answer:

7 0

Your position in meters will, measured relative to the starting point of the car behind you, be
x1(t) = 10 + 23.61 t - 1/2 4.2 t^2
his position will be
x2(t) = 16.67 t
Hence at any time the separation s(t) will be
s(t) = x1(t) - x2(t) = 10 + 6.94 t -2.1 t^2
Now I assume you mean that you will decelerate UNTIl you are driving at the legal speed limit (60 km/h). That will take you:
16.67 m/s = 23.61m/s - 4.2 m/s^2 * t
t = 1.65 seconds
What is the separation at that time? If it is still greater than zero, there will be no collision:
s(1.65) = 10 + 6.94 *1.65 -2.1 (1.65)^2 = 15.73 meters.
Hence you will NOT collide. The 1.65 s you calculated was the time needed to brake to the speed of 60 km/h.

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The drawing shows a large cube (mass = 28.6 kg) being accelerated across a horizontal frictionless surface by a horizontal force

MrRissso [65]

Answer:

P= 454.11 N

Explanation:

Since P is the only horizontal force acting on the system, it can be defined as the product of the acceleration by the total mass of the system (both cubes).

$P= (M+m)*a\\a = \frac{P}{28.6 +4.3}\\a = \frac{P}{32.9}$

The friction force between both cubes (F) is defined as the normal force acting on the smaller cube multiplied by the coefficient of static friction. Since both cubes are subject to the same acceleration:

$F = m * a*\mu \\F= 4.3*0.710*\frac{P}{32.9}\\F=3.053*\frac{P}{32.9}$

In order for the small cube to not slide down, the friction force must equal the weight of the small cube:

$3.053*\frac{P}{32.9} = 4.3 * g\\\\P = \frac{4.3*9.8*32.9}{3.053} \\P= 454.11 N$

The smallest magnitude that P can have in order to keep the small cube from sliding downward is 454.11 N

8 0

3 years ago

Which list of elements contains only metals?

fredd [130]

C. those are all metals.

6 0

3 years ago

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Your roommate drops your wallet down to you from the third-floor window of your apartment, which is 11.5 m from the ground. What

Aneli [31]

Answer:

15 m/s

Explanation:

Using the law of conservation of energy, potential energy equals kinetic energy hence

$mgh=0.5mv^{2}$

Therefore

$v=\sqrt{2gh}$

where g is the acceleration due to gravity, m is the mass of the object, h is the height and v is the speed of the wallet

Taking g as 9.81 then

$v=\sqrt{2\times 9.8\times 11.5}=15.02098532 m/s\approx 15 m/s$

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3 years ago

your friend want to know the amont of salt added to her favorite fast food french fries what would you recommend that she do to

Alexeev081 [22]

That nutritional information is usually not posted up on the wall,
but by federal law, it's available on request, to any customer, at
any fast-food place.

All she has to do is ask to see the manager, and then ask the
manager for the nutritional information booklet.

She'll get a nice printed booklet that tells the salt content in the
fries, AND the amount of many other substances in ALL the items
sold at that place.

It's the law. Don't be bashful.

5 0

3 years ago

Please can someone help me!! It’s so important!!!

Leya [2.2K]

1. is 75 km/h because 150 divided by 2 is 75

3. the second person since he ran the same distance in less time

4. a.True b.False c.True

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3 years ago

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