Jasper didn't want to help out with the dishes. He put off the task toward the end of the day. He even tried to get his

3. What is the velocity of a wave that has a frequency of 750 Hz and a wavelength of 45.7 cm?

sweet-ann [11.9K]

Explanation:

v=(750)(45.7)

v=34275

or

v=(750)(0.457)

v=342.75

3 0

3 years ago

If 27 J of work are needed to stretch a spring from 15 cm to 21 cm and 45 J are needed to stretch it from 21 cm to 27 cm, what i

kupik [55]

Answer:

9 cm.

Explanation:

The energy used for stretch the spring from $15 cm$ to $21 cm$ will be , $E_{1}=27J$

The energy used for stretch the spring from $21 cm$ to $27 cm$ will be , $E_{2}=45J$

using the energy of spring formula ,we find that

$27 = \frac{1}{2}K((21-L^{2})-(15-L^{2}))$

$45 = \frac{1}{2}K((27-L^{2})-(21-L^{2}))$

Dividing both the equation will get,

$\frac{3}{5}=\frac{(21-L)^{2}-(15-L)^{2}}{(27-L)^{2}-(21-L)^{2}}\\5((21-L)^{2}-(15-L)^{2})=3((27-L)^{2}-(21-L)^{2})\\3(729 - 54L + L^{2}- 441 + 42L - L^{2} ) = 5(441 - 42L + L^{2} - 225 + 30L - L^{2} )\\3(288 - 12L) = 5(216 - 12L)\\24L = 216\\L = 9 cm$

Therefore, the natural length of the spring is, 9 cm.

4 0

3 years ago

As shown in the picture above, a sled of mass 67 kilograms is pulled

Scorpion4ik [409]

Explanation:

F net of sled = Tension force by rope - Kinetic friction between ground.

F normal of sled = mg = (67kg)(9.81kg/m^2) = 657.27N.

Kinetic friction = 0.18 (I cannot see the value) * Normal force of sled = 0.18 * 657.27N = 118.31N

So F net of sled = 800N - 118.31N = 681.69N.

(I cannot see what the question is asking for, please check on your own!)

3 0

3 years ago

A ship maneuvers to within 2500 m of an island's 1800 m high mountain peak and fires a projectile at an enemy ship 610 m on the

Ne4ueva [31]

Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions.

t=(0-(250sin75)^2)/-9.8
the distance one is (2500+610)- (250m/s*cos75)*t=Dh Dh=horizontal distance 

the max height one is d=0.5*9.8*t^2 
d= max height subtract 1800-d

3 0

3 years ago

Read 2 more answers

How is the surface area of an average person is 2m^2 in the chapter pressure

11Alexandr11 [23.1K]

Answer:

We have to show surface area $=2m^2$ ,with few conditions that is by considering Force $=200000\ N$ and Pressure $=100000\ Pa$ to be respectively.