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4 years ago

An astronaut weighs 700 N on Earth what is the astronaut's Mass on Earth?

Physics

1 answer:

ch4aika [34]4 years ago

3 0

Answer:

70 kg

Explanation:

On earth, g = 9.8 m/s².

W = mg

700 N = m (9.8 m/s²)

m ≈ 71 kg

Rounded to 1 significant figure, the astronaut's mass is 70 kg.

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A 45-gram object that has a volume of 9 mL has a density of

Elan Coil [88]

The answer : a. 5 g/mL

7 0

3 years ago

The continuity equation shows that the ratio of fluid velocities within different openings is inversely proportional to the cros

Stolb23 [73]

Answer:

A typical example of where the continuity equation can be applied, is in finding the cross sectional area of a laminar falling stream of water from a pipe at an elevation, at the point where it hits the ground.

The speed of the water through the discharge opening of the pipe can be measured with a flow-meter, and the cross sectional opening of the pipe is known.

As the water leaves the pipe, and falls towards the ground, the water stream is accelerated under gravity, and the speed of the water stream increase. The increase in the speed of the water stream causes the cross sectional area to decrease in obedience of the continuity law and equation. If the speed of can be measured, then the area of the water stream just before the water touches the ground can be calculated from the continuity equation.

If the speed of the water stream can not be measured, then it can be calculated using Newton' equation of motion

$v^{2} = u^{2} + 2gz$

$v = \sqrt{u^{2} + 2gz}$

where

v = the velocity of the water stream at the point where it hits the ground

u = the velocity of the water at the pipe discharge (measured with a flow meter in the pipe)

g = acceleration due to gravity

z = the elevation of the pipe above the ground.

After calculating the speed of the water stream at the point where it hits the ground, the cross sectional area of the the stream can be calculated from the continuity equation.

$uA = va$

where

u and v are the velocities of the water stream at the pipe discharge and at the ground respectively.

A = the cross sectional area of the pipe

a = the area of the water stream before it hits the ground.

the equation is simplified as

$a = \frac{uA}{v}$

7 0

4 years ago

The tire of your bicycle needs air so you attach a bicycle pump to it and begin to push down on the pump’s handle. If you exert

dusya [7]

Answer:

12.5 J

Explanation:

Force, F = 25 N

Distance, d = 0.5 m

The direction of force and the displacement is same.

Work is defined as the product of force in the direction of displacement and the displacement.

Work = Force x displacement x CosФ

Where, Ф be the angle between force and the displacement

Here, Ф = 0°

So, W = 25 x 0.5 x Cos0°

W = 12.5 J

6 0

4 years ago

Two cars collide at an intersection. Car A , with a mass of 2000kg , is going from west to east, while car B , of mass 1400kg ,

ahrayia [7]

Complete Question:

Two cars collide at an intersection. Car A , with a mass of 2000 kg, is going from west to east, while car B, of mass 1500 kg, is going from north to south at 15 m/s. As a result, the two cars become enmeshed and move as one. As an expert witness, you inspect the scene and determine that, after the collision, the enmeshed cars moved at an angle of 65∘ south of east from the point of impact. (a) How fast were the enmeshed cars moving just after the collision? (b) How fast was car A going just before the collision?

Answer:

a) 6.36 m/s b) 4.57 m/s

Explanation:

a) Assuming no external forces acting during the collision, total momentum must be conserved.

As momentum is a vector, we can decompose it along two directions perpendicular each other.

Just for convenience, we choose as our x-axis to the W-E direction, and as our y-axis, the direction N-S.

If we know that total momentum must be conserved, same must be true for both components, px and py.

Applying the information provided (both cars become enmeshed after the collision, moving at an angle of 65º south of east from the point of impact), we have:

px = ma * va = (ma+mb) * vab * cos 65º (1)

py = mb * vb = (ma + mb) * vab * sin 65º (2)

Replacing by the values of ma, mb, and sin 65º, we can solve for vab, as follows:

vab = 1,400 kg* 14.0 m/s / (3,400 Kg * sin 65º) = 6.36 m/s

b) Replacing vab from above in (1), and solving for va, we have:

va = 3,400 kg* 6.36 m/s* cos 65º / 2,000 Kg = 4.57 m/s

7 0

3 years ago

Hydroelectric power is produced by

scoundrel [369]

Hydro electric power is the process of production of electricity from the mechanical energy of water.

In the process of generation of hydro electricity ,large dams are constructed in which the water is stored.The water present at top of the dam has potential energy.The water is driven downward with high pressure. During the falling of water,the potential energy of the water is converted into equivalent kinetic energy. The water coming down with a heavy speed is allowed to fall on a turbine which is connected to a generator.

The mechanical energy of water drives the turbine and electricity is generated due to the electromagnetic induction .

Hence the option A is right i.e falling water that turns the turbine.

7 0

4 years ago