If the_____of a wave increases, its frequency must decrease.

A rugby player passes the ball 7.88 m across the field, where it is caught at the same height as it left his hand. (Assume the p

damaskus [11]

Explanation:

Given

Range of ball =7.88 m

Initial speed=13.1 m/s

and we know

Range of Projectile is

$R=\frac{u^2sin2\theta }{g}$

$13.1=\frac{13.1^2\times sin2\theta }{9.8}$

$7.88\times 9.8=13.1^2\times sin2\theta$

$sin2\theta =0.4499$

$2\theta =26.74^{\circ}$

$\theta =13.37 ^{\circ}$

(b)other angle would be complementary of $\theta$

$=90-\theta =76.63 ^{\circ}$

8 0

3 years ago

An ion's position vector is initially r with arrow = 7.0i hat â 7.0j + 1.0k, and 5.0 s later it is r with arrow = 7.0i hat + 7.0

harkovskaia [24]

<h2>Answer:</h2>

Shown in the explanation

<h2>Explanation:</h2>

Position vector of a particle at a given instant is given by:

$\vec{r}=x\hat{i}+y\hat{j}+z\hat{k}$

On the other hand, the average velocity is the change in the particle’s position vector divided by time interval:

$\vec{v}=\frac{\Delta \vec{r}}{\Delta t}=\frac{\vec{r_{2}}-\vec{r_{1}} }{t_{2}-t_{1}} \\ \\ \\ Where: \\ \\ \\ \vec{r_{1}}: Initial \ position \\ \\ \vec{r_{2}}: Final \ position \\ \\ t_{1}:Initial \ time \\ \\ t_{2}:Final \ time$

So we have:

$\vec{r_{1}}=7\hat{i}+7\hat{j}+1\hat{k} \\ \\ \vec{r_{2}}=7\hat{i}+7\hat{j}+8\hat{k} \\ \\ \\ Then: \\ \\ \Delta \vec{r} = \vec{r_{2}}-\vec{r_{1}}=7\hat{i}+7\hat{j}+8\hat{k}-(7\hat{i}+7\hat{j}+1\hat{k}) \\ \\ \Delta \vec{r}=7\hat{k} \\ \\ \\ We \ also \ know: \\ \\ \Delta t=5s$

Finally, the average velocity is:

$\vec{v}=\frac{\Delta \vec{r}}{\Delta t} \\ \\ \\ \vec{v}=\frac{7\hat{k}}{5} \\ \\ \boxed{\vec{v}=\frac{7}{5}\hat{k} \ units/s}$

3 0

4 years ago

Sarah, whose mass is 40 kg, is on her way to school after a winter storm when she accidentally slips on a patch of ice whose coe

RideAnS [48]

Sarah's acceleration is $-0.49 m/s^2$

Explanation:

The force of kinetic friction acting on Sarah has a magnitude which is given by:

$F_f = \mu mg$

where

$\mu$ is the coefficient of kinetic friction

m is Sarah's mass

g is the acceleration of gravity

Moreover, according to Newton's second law of motion, we know that the net force on Sarah is equal to its mass times its acceleration:

$F=ma$

where a is the acceleration

Since the force of friction is the only force acting on Sarah, we can say that the net force is equal to the force of friction, therefore:

$F=-\mu mg = ma$

where the negative sign is due to the fact that the force of friction has a direction opposite to the motion of Sarah. Solving for a, we find

$a=-\mu g$

And substituting the following values:

$\mu = 0.05$ (coefficient of friction)

$g=9.81 m/s^2$ (acceleration of gravity)

we find:

$a=-(0.05)(9.81)=-0.49 m/s^2$

Learn more about acceleration and forces:

brainly.com/question/11411375

brainly.com/question/1971321

brainly.com/question/2286502

brainly.com/question/2562700

#LearnwithBrainly

4 0

3 years ago

Plz help ASAP I will give brainliest PLZ

Natasha2012 [34]

Answer:

1.8m/s^2

Explanation:

Since the two ropes are going up, their combined force is 105+115=220N. With a gravitational force of 186N, the force of the two ropes pulling up the will be 220-186=34N.

Now we need the mass of the bucket itself in order to find the acceleration of the bucket (remember that F=ma and m is needed to find a). Since gravitational acceleration is 9.8m/s^2 and F=186N, 186/9.8=18.97959184 kg for the mass of the bucket.

Now that we have the mass of the bucket, we can find the acceleration of the bucket. Since F=34N from earlier, 34N/18.97959184kg=1.791397849m/s^2=1.8m/s^2 is the acceleration of the bucket.

Therefore, 1.8m/s^2 is the correct answer.

Please mark brainliest!

4 0

3 years ago

Read 2 more answers

Given the following frequencies, calculate the corresponding periods. a. 60 Hz b. 8 MHz c. 140 kHz d. 2.4 GHz

Ipatiy [6.2K]

The frequency can be defined as the inverse of the period, that is, it can be expressed as

$T = \frac{1}{f}$