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4 years ago

How do I find initial velocity and time?

Physics

1 answer:

forsale [732]4 years ago

3 0

Explanation:

Given:

Δx = -100

v = 10

a = 20

To find v₀, use a kinematic equation that's independent of time.

v² = v₀² + 2aΔx

(10)² = v₀² + 2(20)(-100)

100 = v₀² − 4000

v₀² = 4100

v₀ = ±64.0

As your teacher said, v₀ can't be +64.0. So v₀ = -64.0.

Next, to find time, use a kinematic equation that's independent of initial velocity.

Δx = vt − ½ at²

-100 = (10) t − ½ (20) t²

-100 = 10 t − 10 t²

-10 = t − t²

t² − t − 10 = 0

Solve with quadratic formula:

t = [ -(-1) ± √((-1)² − 4(1)(-10)) ] / 2(1)

t = (1 ± √41) / 2

t > 0, so:

t = (1 + √41) / 2

t ≈ 3.70

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The x component of vector is -27.3 m and the y component is +43.6 m. (a) What is the magnitude of ? (b) What is the angle betwee

lara [203]

Answer:51.44 units

Explanation:

Given

x component of vector is $-27.3\hat{i}$

y component of vector is $43.6\hat{j}$

so position vector is

$r=-27.3\hat{i}+43.6\hat{j}$

Magnitude of vector is

$|r|=\sqrt{27.3^2+43.6^2}$

$|r|=\sqrt{2646.25}$

|r|=51.44 units

Direction

$tan\theta =\frac{43.6}{-27.3}=-1.597$

vector is in 2nd quadrant thus

$180-\theta =57.94$

$\theta =122.06^{\circ}$

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3 years ago

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MAVERICK [17]

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S_A_V [24]

1) Average speed

2) Displacement

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Speed is a scalar quantity which gives a measure of how fast a body is moving. It is equal to the ratio between the distance travelled by an object and the time taken to cover that distance:

$speed = \frac{d}{\Delta t}$

where

d is the distance covered

$\Delta t$ is the time taken

It is important to note that being a scalar, speed does not have any direction. Moreover, distance is also a scalar quantity, which corresponds to the total length of the path covered by the object, regardless on the direction taken.

So, the equation "travelled distance/elapsed time" corresponds to the average speed. (where the term average refers to the fact we are not measuring the speed at a specific instant in time, but on a certain time interval $\Delta t$ .

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The magnitude of the velocity is given by:

$velocity=\frac{\Delta x}{\Delta t}$

where

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Learn more about speed and velocity:

brainly.com/question/8893949 (speed)

brainly.com/question/5063905 (speed vs velocity)

brainly.com/question/5248528 (velocity)

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4 years ago

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JulsSmile [24]

Answer:

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