The semi-major axis of this ellipse is 8.8 cm, and the distance from one of the foci to the

Danny lowers the sails on his boat. He paddles upstream at 19 km/hr. The current is still running downstream at 15 km/hr. What i

Molodets [167]

Answer:

4 km/hr

Explanation:

The computation of the actual velocity is shown below:

Because the path of its paddles is opposed to the current direction, the real velocity can be determined by deducting the current velocity to its velocity while paddling

So, the actual velocity is

= Upstream - downstream

= 19 km/hr - 15 km/hr

= 4 km/hr

As we can see it is in positive, so it is an upstream direction

3 0

3 years ago

What quantity is represented by a unit called a newton (N)?

zavuch27 [327]

$\textsf {C. Force}$

$\textsf {The quantity which is represented by a unit called Newton (N)}\\\textsf {is Force.}$

5 0

2 years ago

A student team is to design a human powered submarine for a design competition. The overall length of the prototype submarine is

Allushta [10]

Answer:

a) The speed is 61.42 m/s

b) The drag force is 10.32 N

Explanation:

a) The Reynold´s number for the model and prototype is:

$Re_{m} =\frac{p_{m}V_{m}L_{m} }{u_{m} }$

$Re_{p} =\frac{p_{p}V_{p}L_{p} }{u_{p} }$

Equaling both Reynold's number:

$\frac{p_{p}V_{p}L_{p} }{u_{p} }=\frac{p_{m}V_{m}L_{m} }{u_{m} }$

Clearing Vm:

$V_{m} =\frac{p_{p}V_{p}L_{p} u_{m} }{u_{p} p_{m} L_{m} }=\frac{999.1*0.56*8*1.849x10^{-5} }{1.138x10^{-3}*1.184*1 } =61.42m/s$

b) The drag force is:

$\frac{F_{Dm} }{p_{m}V_{m}^{2}L_{m}^{2} } =\frac{F_{Dp} }{p_{p}V_{p}^{2}L_{p}^{2} } \\F_{Dp} =\frac{F_{Dp}p_{p}V_{p}^{2}L_{p}^{2} }{p_{m}V_{m}^{2}L_{m}^{2} } \\F_{Dp}=\frac{2.3*999.1*0.56^{2} *8^{2} }{1.184*61.42^{2}*1^{2} } =10.32N$

6 0

3 years ago

Read 2 more answers

Two speakers emit the same sound wave, identical frequency, wavelength, and amplitude. What other quantity would be necessary to

Komok [63]

Answer:

Phase Difference

Explanation:

When the sound waves have same wavelength, frequency and amplitude we just need the phase difference between them at a particular location to determine whether the waves are in constructive interference or destructive interference.

Interference is a phenomenon in which there is superposition of two coherent waves at a particular location in the medium of propagation.

When the waves are in constructive interference then we get a resultant wave of maximum amplitude and vice-versa in case of destructive interference.