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Aleonysh [2.5K]

3 years ago

12

For work to be accomplished we must have?

1 answer:

KiRa [710]3 years ago

4 0

Answer:

a force and a movement in the same direction as the force.

Explanation:

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Which quantity must equal zero if a car is moving at a constant rate along a straight line?

Virty [35]

B the energy of the car. Sorry if this is not right

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3 years ago

Scientists take scientific measurements carefully in order to ensure that reliability and validity. What is the difference betwe

Gala2k [10]

Accuracy describes how close a measurement is to the truest value while precision shows how close the measurements are to one another when repeated analysis of the same measurements are performed. Precision most likely is free from any any variation.

7 0

3 years ago

A Neglecting air resistance, a ball projected straight upward so it remains in the air for 10 seconds needs an initial speed of

ololo11 [35]

Answer:

The initial velocity is 50 m/s.

(C) is correct option.

Explanation:

Given that,

Time = 10 sec

For first half,

We need to calculate the height

Using equation of motion

$v^2=u^2+2gh$

$h =\dfrac{v^2}{2g}$ ....(I)

For second half,

We need to calculate the time

Using equation of motion

$h =ut+\dfrac{1}{2}gt_{2}^2$

$h=0+\dfrac{1}{2}gt_{2}^2$

$t_{2}=\sqrt{\dfrac{2h}{g}}$

Put the value of h from equation (I)

$t_{2}=\sqrt{\dfrac{2\times v^2}{g^2}}$

$t_{2}=\dfrac{v}{g}$

According to question,

$t_{1}+t_{2}=10$

$t_{1}=t_{2}$

Put the value of t₁ and t₂

$\dfrac{v}{g}+\dfrac{v}{g}=10$

$\dfrac{2v}{g}=10$

$v=\dfrac{10\times g}{2}$

Here, g = 10

The initial velocity is

$v=\dfrac{10\times10}{2}$

$v=50\ m/s$

Hence, The initial velocity is 50 m/s.

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3 years ago

IS IT WRONG TO FOLLOW SOMEONE ON TIKTOK?!?!?!?!?!??

mariarad [96]

No it’s not follow me ;)

4 0

3 years ago

Read 2 more answers

Speakers A and B are vibrating in phase. They are directly facing each other, are 8.2 m apart, and are each playing a 78.0 Hz to

Stels [109]

Answer:6.298,4.1,1.9015

Explanation:

Wavelength= $\frac{velocity of sound }{frequency}$

= $\frac{343}{78}$ =4.397 m

Distance of 3rd speaker from speaker A is x

From B 78-x

Difference between the distances must be a whole number of wavelengths

First

$x-\left ( 8.2-x\right )=4.397$ for 1 st wavelength

2x=8.2+4.397=12.597

x=6.298m

second

For zero wavelength

$x-\left ( 8.2-x\right )=0$

2x=8.2

x=4.1m

Third

$\left ( 8.2-x\right )-x=4.397$

x=1.9015 m

6 0

3 years ago