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2 years ago

Is work done in this example: A student lifting a heavy backpack off of the floor.

Physics

2 answers:

vagabundo [1.1K]2 years ago

4 0

I don't know what u mean

Maru [420]2 years ago

3 0

You need to add more explaintion of what you are talking about

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The main equation we are using to measure the e/m ratio is:

kow [346]

Answer:

Explanation:

the electrons beams deflection radius will be halved.

6 0

3 years ago

An object moving in circular motion has a mass of 15 kg and a centripetal acceleration of 10 m/s2. What is the centripetal force

sweet-ann [11.9K]

Answer:

1) A

2) C

3) B

4) A

5) Incomplete information(picture missing)

6) Incomplete information(picture missing)

7) Incomplete information(picture missing)

8) A

9) C

10) C

Explanation:

1) m = 15kg, a = $10ms^{-2}$ , F = ma = 15*10 = 150N

2) m = 3kg, v = $4ms^{-1}$ , r = 4m, F = $\frac{mv^{2} }{r}$

$\frac{3*4^{2} }{4}$ = 12N

3) a = $10ms^{-2}$ , r = 10m, v=?

F = $\frac{mv^{2} }{r}$ and F = ma

equating the two equations and cancelling a, we have:

$\frac{v^{2} }{r}$ = a

making v the subject of formula, we have:

v = $\sqrt{ar}$

= $\sqrt{100}$

= 10 $ms^{-1}$

4) r = 10m, v = $5ms^{-1}$ , a = ?

F = $\frac{mv^{2} }{r}$

F = ma

equating the above equations and making a subject of formula, we get:

a = $\frac{v^{2} }{r}$

a = 25/10 = 2.5 $ms^{-2}$

5) I can't find the picture associated with this question

6) I can't find the picture associated with this question

7) I can't find the picture associated with this question

8) F = $\frac{mv^{2} }{r}$

assuming m and r is unity, that is the values are 1 respectively, the formula simplifies to:

F = $v^{2}$

Now, if v is tripled

F = $(3v)^{2}$

F = 9 $v^{2}$

We can see that the force will be 9X greater than it was.

9) F = $\frac{mv^{2} }{r}$

assuming m and r is unity, that is the values are 1 respectively, the formula simplifies to:

F = $v^{2}$

Now, if v is doubled

F = $(2v)^{2}$

F = 4 $v^{2}$

We can see that the force will be 4X greater than it was.

10) F = $\frac{mv^{2} }{r}$

assuming m and v is unity, that is the values are 1 respectively

F = 1/r

if r is doubled,

F = 1/2 * 1/r

We can see that the force is 1/2 as big as it was

7 0

3 years ago

Two speakers, one directly behind the other, are each generating a 240-Hz sound wave. What is the smallest separation distance b

AveGali [126]

Answer:

The smallest separation distance between the speakers is 0.71 m.

Explanation:

Given that,

Two speakers, one directly behind the other, are each generating a 240-Hz sound wave, f = 240 Hz

Let the speed of sound is 343 m/s in air. The speed of sound is given by the formula as :

$v=f\lambda\\\\\lambda=\dfrac{v}{f}\\\\\lambda=\dfrac{343\ m/s}{240\ Hz}\\\\\lambda=1.42\ m$

To produce destructive interference at a listener standing in front of them,

$d=\dfrac{\lambda}{2}\\\\d=\dfrac{1.42}{2}\\\\d=0.71\ m$

So, the smallest separation distance between the speakers is 0.71 m. Hence, this is the required solution.

3 0

3 years ago

Read 2 more answers

In loading a lorry, a man lifts boxes each of weight 100N through a height of 1.5m.

liq [111]

Answer:

The amount of work done in order to lift the box is $150\ Joule$

Explanation:

Given the weight of each box is $100N$

And the man lifts boxes at a height of $1.5m$

We need to find the amount of work done.

The amount of work done is the product of applied force $F$ that causes the displacement $d$ .

In our problem force is $100N$ and displacement is $1.5m$ .

Now, work done

$=force\times displacement\\=100\times1.5\\=150\ Joule$

So, the amount of work done in order to lift the box is $150\ Joule$

5 0

3 years ago

If the velocity is constant, describe the the slope of the graph on a position vs. time graph.

kvv77 [185]

If the velocity is constant, then the position/time graph has a constant slope, meaning a straight line.

The slope may be any constant value ... positive, negative, or zero.

-∞ < slope < +∞

5 0

3 years ago

Read 2 more answers