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3 years ago

Which will result in positive buoyancy and cause the object to float?

Physics

2 answers:

Wewaii [24]3 years ago

4 0

the answer should be:

When the buoyant force is equal to the force of gravity

natali 33 [55]3 years ago

4 0

The answer is when the buoyant force is greater than gravity

You might be interested in

When different resistors are connected in parallel across an ideal battery, we can be certain that: a) their equivalent resistan

sergeinik [125]

Answer:

b) the potential difference across each is the same.

Explanation:

When resistors are connected in parallel with each other

then the terminals of all the resistors will connected across the terminals of the battery

So we know the potential difference of the battery is same across all the resistors

So we can say that the equivalent resistance of all the resistance is

$\frac{1}{R} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3}$

so its not the mean of all resistors

also we know that the resistance are all different so power across each resistance is different given as

$P = \frac{V^2}{R}$

also current in each resistance is also different and given by

$i = \frac{V}{R}$

so correct answer will be

b) the potential difference across each is the same.

5 0

3 years ago

A football punter wants to kick the ball so that it is in the air for 4.2 s and lands 55 m from where it was kicked. Assume that

earnstyle [38]

Answer:

$57.24^{\circ}$

24.21 m/s

Explanation:

x = Displacement in x direction = 55 m

y = Displacement in x direction = 0

$y_0$ = Height of the ball when the ball is kicked = 1 m

t = Time taken = 4.2 s

$a_y=g$ = Acceleration due to gravity = $-9.81\ \text{m/s}^2$

u = Initial velocity of ball

Displacement in x direction is given by

$x=u_xt+\dfrac{1}{2}a_xt^2\\\Rightarrow 55=4.2u_x+0\\\Rightarrow u_x=\dfrac{55}{4.2}\\\Rightarrow u\cos\theta=13.1\ \text{m/s}\\\Rightarrow u=\dfrac{13.1}{\cos\theta}$

Displacement in y direction is given by

$y=y_0+u_yt+\dfrac{1}{2}a_yt^2\\\Rightarrow 0=1+4.2u\sin\theta+\dfrac{1}{2}\times (-9.81)\times 4.2^2\\\Rightarrow 0=4.2u\sin\theta-85.5242\\\Rightarrow u\sin\theta=20.36\ \text{m/s}\\\Rightarrow u=\dfrac{20.36}{\sin\theta}$

$\dfrac{13.1}{\cos\theta}=\dfrac{20.36}{\sin\theta}\\\Rightarrow \dfrac{20.36}{13.1}=\dfrac{\sin\theta}{\cos\theta}\\\Rightarrow \theta=\tan^{-1}\dfrac{20.36}{13.1}\\\Rightarrow \theta=57.24^{\circ}$

The ball should be kicked at an angle of $57.24^{\circ}$

$u=\dfrac{13.1}{\cos\theta}=\dfrac{13.1}{\cos57.24^{\circ}}\\\Rightarrow u=24.21\ \text{m/s}$

The initial speed of the ball is 24.21 m/s.

3 0

3 years ago

A block of mass 2 kg is placed on the floor. The coefficient of static friction is 0.4. A horizontal force of 2.5 N is applied o

Masja [62]

Answers is F=7.84 N

Friction force resists the effect of horizontal force and trying to approch to a limiting force.

we have formula for limiting friction force between block and floor

F=Ц N

where N=mg

putting values we get answer.

Download pdf

3 0

3 years ago

Which part of the electromagnetic spectrum have the highest level of photon energy

Pani-rosa [81]

The energy carried by one photon is directly proportional to its
frequency. So the photon energy is greatest for the electromagnetic
waves with the highest frequency / shortest wavelengths.

That's why when you get past visible light and on up through ultraviolet,
X-rays, and gamma rays, the radiation becomes dangerous ==> each
photon carries enough energy to tear electrons away from their atoms,
ripping molecules apart and damaging cells.

The photon with the highest energy is a gamma-ray photon.

4 0

3 years ago

True or False: As distance between 2 objects increases, the gravitational force decreases

VikaD [51]

Answer:

True

Explanation:

Because it is:)

5 0

3 years ago