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3 years ago

A 20 kg mass is dropped from a tall rooftop and accelerates at 9.8 m/s2. What is the weight of the dropped object?

2 answers:

7 0

It would have no “weight” since weight is determined by the force normal and since it is accelerating there is no normal force making it weightless

patriot [66]3 years ago

6 0

Objects in free fall are weightless.

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An object moves in the eastward direction at constant speed. A net force directed northward acts on the object for 5.0 s. At the

Pie

Answer: D

The final velocity of the object will be directed north of east

Explanation:

8 0

4 years ago

Read 2 more answers

A body weights 50 N in air and 45 N when wholly immersed in water calculate (i) the loss in weight of the body in water (ii) the

Lelechka [254]

Answer:

$difference \: in \: weight = 150n - 100n = 50n$

Now,buyantant force

$difference \: in \: weight \: = volume(body) \times density \: of \: water \: \times g$

so;

$50 = {v}^{b} \times 1 \times {10}^{3} \times 9.8m {s}^{2}$

${v}^{b} = \frac{50}{1000 } \times 9.8$

$= \frac{50}{9800}$

$= 0.0051$

Now,

$mass \: in \: air \: = 150n = \frac{150}{9.8kg}$

$density = \frac{weght}{volume}$

$= \frac{150}{0.0051} \times 9.8 \\ x = 3000$

And now,

$specific \: density \: = \frac{density of \: the \: body}{density \: of \: water}$

$= \frac{3000}{1000}$

$= 3$

Hence that,specific density of a given body is 3

please mark me as brainliest, please

3 0

3 years ago

A block has a volume of 0.09 m3 and a density of 4,000 kg/m3. What's the force of gravity acting on the block in water?

12345 [234]

   Density = (mass) / (volume)

      4,000 kg/m³ = (mass) / (0.09 m³)

Multiply each side
by 0.09 m³ :           (4,000 kg/m³) x (0.09 m³) = mass

   mass = 360 kg .

Force of gravity = (mass) x (acceleration of gravity)

   = (360 kg) x (9.8 m/s²)

   = (360 x 9.8) kg-m/s²

   = 3,528 newtons .

That's the force of gravity on this block, and it doesn't matter
what else is around it. It could be in a box on the shelf or at
the bottom of a swimming pool . . . it's weight is 3,528 newtons
(about 793.7 pounds).

Now, it won't seem that heavy when it's in the water, because
there's another force acting on it in the upward direction, against
gravity. That's the buoyant force due to the displaced water.

The block is displacing 0.09 m³ of water. Water has 1,000 kg of
mass in a m³, so the block displaces 90 kg of water. The weight
of that water is (90) x (9.8) = 882 newtons (about 198.4 pounds),
and that force tries to hold the block up, against gravity.

So while it's in the water, the block seems to weigh

   (3,528 - 882) = 2,646 newtons (about 595.2 pounds) .

But again ... it's not correct to call that the "force of gravity acting
on the block in water". The force of gravity doesn't change, but
there's another force, working against gravity, in the water.

5 0

3 years ago

Read 2 more answers

The gravitational force,F, on a rocket at a distance,r, from the center of the earth isgiven byF=kr2wherek= 1013N·km2. (Newton·k

Brrunno [24]

Answer:

The gravitational force changing velocity is

$\frac{dF}{dt}=-8\frac{N}{s}$

Explanation:

The expression for the gravitational force is

$F=\frac{k}{r^{2}}\\\\k=10x10^{13} N*km^{2}\\\\r=10x10^{4} km\\\\V=0.4 \frac{km}{s}$

Differentiate the above equation

$\frac{dF}{dt}=\frac{k}{r^{2}}\\\frac{dF}{dt}=k*r^{-2}\\\frac{dF}{dt}=-2*k*r^{-3} \frac{dr}{dt}\\\frac{dF}{dt}=\frac{-2k}{r^{3}}\frac{dr}{dt}$

The velocity is the distance in at time so

$V=\frac{dr}{dt}=0.4 \frac{km}{s}$

$\frac{dF}{dt}=\frac{-2*k}{r^{3}}*0.4\\\frac{dF}{dt}=\frac{-8*10x^{13}N*km^{2} }{(10x10^{4}) ^{3}} \\\frac{dF}{dt}=\frac{-8x10^{12} }{1x10^{12}}$

$\frac{dF}{dt}=-8\frac{N}{s}$

8 0

3 years ago

As charges move in a closed loop, they

mamaluj [8]

As charges move in a closed loop, they gain as much energy as they lose.

<h3>What is principle of conservation of energy?</h3>

According to the principle of conservation of energy, in a closed or isolated system, the total energy of the system is always conserved.

The energy gained by the particles or charges in a closed system is equal to the energy lost by the charges.

Thus, we can conclude the following based on principles of conservation of energy;

As charges move in a closed loop, they gain as much energy as they lose.

Learn more about conservation of energy here: brainly.com/question/166559

8 0

2 years ago