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2 years ago

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A hockey puck is pushed by a stick with a force of 750 newtons. The puck travels 2.0 meters in 0.30 seconds. How powerful is the

push? (Ignore frictional effects.)

1 answer:

nekit [7.7K]2 years ago

5 0

The work done by the force pushing the puck is equal to the product between the force and the distance covered:
$W=Fd=(750 N)(2.0 m)=1500 J$

And the power is the work done per unit time:
$P= \frac{W}{t}$
and using t=0.30 s, we find the power:
$P= \frac{1500 J}{0.30 s}=5000 W$

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Two rigid rods are oriented parallel to each other and to the ground. The rods carry the same current in the same direction. The

Greeley [361]

Answer:

I = 215.76 A

Explanation:

The direction of magnetic field produced by conductor 1 on the location of conductor 2 is towards left. Based on Right Hand Rule -1 and taking figure 21.3 as reference, the direction of force Fm due to magnetic field produced at C_2 is shown above. The force Fm balances the weight of conductor 2.

Fm = u_o*I^2*L/2*π*d

where I is the current in each rod, d = 0.0082 m is the distance 27rId

between each, L = 0.85 m is the length of each rod.

Fm = 4π*10^-7*I^2*1.1/2*π*0.0083

The mass of each rod is m = 0.0276 kg

F_m = mg

4π*10^-7*I^2*1.1/2*π*0.0083=0.0276*9.8

I = 215.76 A

note:

mathematical calculation maybe wrong or having little bit error but the method is perfectly fine

5 0

1 year ago

What type of wave cannot travel in a vacuum

lions [1.4K]

A sound wave. Because in a vacuum there is no medium in a vacuum. And the only wave that requires a medium to travel through is a sound wave.

5 0

2 years ago

Read 2 more answers

Calculate the work WC done by the gas during the isothermal expansion. Express WC in terms of p0, V0, and Rv.

mote1985 [20]

Complete Question

The complete question is shown on the first and second uploaded image

Answer:

The expression is $W_c = P_o V_o ln (R_v)$

Explanation:

Generally smallest workdone done by a gas is mathematically represented as

$dW = PdV$

Generally for an isothermal process

$PV = nRT = constant$

=> $P = \frac{nRT}{V}$

Generally the total workdone is mathematically represented as

$W_c = \int\limits^{v_f}_{V_o} {\frac{nRT}{V} } \, dV$

=> $W_c = nRT \int\limits^{V_f}_{V_o} {\frac{1}{V} } \, dV$

=> $nRT [lnV] | \left \ {V_f}} \atop {V_o}} \right.$

=> $W_c = nRT [ln(V_f) - ln(V_o)]$

=> $W_c = nRT ln \frac{V_f}{V_o}$

From the question $\frac{V_f}{V_o } = R_v$

=> $W_c = P Vln (R_v)$

at initial state

$W_c = P_o V_o ln (R_v)$

7 0

1 year ago

A machine is designed to fill jars with 16 ounces of coffee. A consumer suspects that the machine is not filling the jars comple

babunello [35]

Answer:

a) Null hypothesis: $\mu \geq 16$

Alternative hypothesis : $\mu$

b) $t=\frac{15.6-16}{\frac{0.3}{\sqrt{8}}}=-3.77$

$p_v =P(t_{(7)}$

If we compare the p value and the significance level given $\alpha=0.1$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis.

c) We can conclude that the mean is significantly less than 16 ounces at 10% of significance. so then the consumer suspect is correct.

Explanation:

Data given and notation

$\bar X=15.6$ represent the mean for the sample

$s=0.3$ represent the sample standard deviation

$n=8$ sample size

$\mu_o =16$ represent the value that we want to test

$\alpha=0.1$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

Is a one tailed left test.

What are H0 and Ha for this study?

Null hypothesis: $\mu \geq 16$

Alternative hypothesis : $\mu$

The degrees of freedom on this case are:

$df=n-1=8-1=7$

Compute the test statistic

The statistic for this case is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$t=\frac{15.6-16}{\frac{0.3}{\sqrt{8}}}=-3.77$

Give the appropriate conclusion for the test

Since is a one side left tailed test the p value would be:

$p_v =P(t_{(7)}$

Conclusion

If we compare the p value and the significance level given $\alpha=0.1$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis.

We can conclude that the mean is significantly less than 16 ounces at 10% of significance. so then the consumer suspect is correct.

3 0

1 year ago

A ball is thrown upward from the top of a 25.0 m tall building. The ball’s initial speed is 12.0 m/sec. At the same instant, a p

zimovet [89]

<h2>Person must have 8.18 m/s to catch the ball</h2>

Explanation:

Consider the vertical motion of ball

We have equation of motion s = ut + 0.5at²

Initial velocity, u = 12 m/s

Acceleration, a = -9.81 m/s²

Displacement, s = -25 m

Substituting

-25 = 12 x t + 0.5 x -9.81 x t²

4.905 t² -12t - 25 = 0

t = 3.79 sec

Ball hits ground after 3.79 seconds.

So person need to cover 31 m in 3.79 seconds

Consider the horizontal motion of person

We have equation of motion s = ut + 0.5at²

Initial velocity, u = ?

Acceleration, a = 0 m/s²

Displacement, s = 31 m

Time, t = 3.79 seconds

Substituting

31 = u x 3.79 + 0.5 x 0 x 3.71²

u = 8.18 m/s

Person must have 8.18 m/s to catch the ball

6 0

1 year ago