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3 years ago

How can we tell when forces are acting on an object (science)

1 answer:

4 0

If an object's speed changes, or if it changes the direction it's moving in,
then there must be forces acting on it. There is no other way for any of
these things to happen.

Once in a while, there may be a group of forces (two or more) acting on
an object, and the group of forces may turn out to be "balanced". When
that happens, the object's speed will remain constant, and ... if the speed
is not zero ... it will continue moving in a straight line. In that case, it's not
possible to tell by looking at it whether there are any forces acting on it.

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What are the structures shown below ??

forsale [732]

The body system on the chart

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3 years ago

Can you be fluid overload and dehydrated at the same time

STALIN [3.7K]

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3 years ago

a whistle you use to call your hunting dog has a frequency of 21 khz, but your dog is ignoring it. you suspect the whistle may n

laila [671]

To solve this problem we will apply the concepts related to the Doppler effect. According to this concept, it is understood as the increase or decrease of the frequency of a sound wave when the source that produces it and the person who captures it move away from each other or approach each other. Mathematically this can be described as

$f = f_0 (\frac{v-v_0}{v})$

Here,

$f_0$ = Original frequency

$v_0$ = Velocity of the observer

$v$ = Velocity of the speed

Our values are,

$v = 340m/s \rightarrow \text{Speed of sound}$

$f = 20kHz \rightarrow \text{Apparent frequency}$

$f_0 = 21kHz \rightarrow \text{Original frequency}$

Using the previous equation,

$f = f_0 (\frac{v-v_0}{v})$

Rearrange to find the velocity of the observer

$v_0 =v (1-\frac{f}{f_0})$

Replacing we have that

$v_0= (340m/s)(1-\frac{20kHz}{21kHz})$

$v_0 = 16.19m/s$

Therefore the velocity of the observer is 16.2m/s

4 0

3 years ago

What is the minimum speed needed to fire a champagne cork a distance of 11m?

Crank

To start with solving this problem, let us assume a launch angle of 45 degrees since that gives out the maximum range for given initial speed. Also assuming that it was launched at ground level since no initial height was given. Using g = 9.8 m/s^2, the initial velocity is calculated using the formula:

(v sinθ)^2 = (v0 sinθ)^2 – 2 g d

where v is final velocity = 0 at the peak, v0 is the initial velocity, d is distance = 11 m

Rearranging to find for v0: 
v0 = sqrt (d * g/ sin(2 θ))

v0 = 10.383 m/s

8 0

3 years ago

Why is the ionic compound magnesium chloride neutral

shutvik [7]

Answer: The charges on cation and anion balances each other.

Explanation:

For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.

$Mg:12:1s^22s^22p^63s^2$

$Mg^{2+}:10:1s^22s^22p^6$

$Cl:17:1s^22s^22p^63s^23p^5$

$Cl^{-}:18:1s^22s^22p^63s^23p^6$

Thus $Mg^{2+}$ combines with two $Cl^-$ ions to give neutral $MgCl_2$

8 0

3 years ago