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Angelina_Jolie [31]

2 years ago

5

1. A rocket is forced forward by the ______ force of its engines, expelling gases out the rear of the rocket.

1 answer:

AURORKA [14]2 years ago

6 0

There are two forces acting on a rocket at the moment of lift off: Thrust pushes the rocket upwards by pushing gases downwards in the opposite direction.Weight is the force due to gravity pulling the rocket downwards towards the centre of the earth.So I'm thinking the answer is THRUST.

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620 J of heat is added to the cylinder of an engine, which causes the gas inside to expand. As a result, the piston of the engin

Maru [420]

Answer:

<u>400</u> J work is done BY the engine.

The internal energy of the gas is <u>620</u> J

Explanation:

The given information are;

The heat added to the cylinder = 620 J

The force applied by the piston of the engine = 8.0 kN = 8,000 N

The distance over which the force moves (the piston) = 5.0 cm = 0.05 m

The work done (by the engine) = Force × Distance = 8,000 N × 0.05 m = 400 J

The internal energy is the sum of the kinetic and potential energy of the system

Therefore, given that the internal energy, U, is the sum total of the energy in the system

∴ U = The heat supplied to the system = 620 J

Which gives;

<u>400</u> J work is done BY the engine.

The internal energy of the gas is <u>620</u> J.

6 0

2 years ago

Your job is to lift 30 kgkg crates a vertical distance of 0.90 mm from the ground onto the bed of a truck. For related problem-s

Gekata [30.6K]

Answer:

The number of crates is 84580.

Explanation:

mass, m = 30 kg

height, h = 0.9 mm

Power, P = 0.5 hp = 0.5 x 746 W = 373 W

time, t = 1 minute = 60 s

Let the number of crates is n.

Power is given by the rate of doing work.

$P = \frac{n m gh}{t}\\\373 =\frac{n\times 30\times9.8\times 0.9\times 10^{-3}}{60}\\\\n =84580$

7 0

2 years ago

Which diagram best shows the field lines around two bar magnets attracting<br> each other?

Marizza181 [45]

I think the answer is C

5 0

2 years ago

What theory did dalton propose about the structure of matter

Irina-Kira [14]

Dalton’s atomic theory proposed that all matter was composed of atoms

8 0

3 years ago

Read 2 more answers

A sled of mass 80 kg starts from rest and slides down an 18° incline 90 m long. It then travels for 20 m horizontally before sta

yaroslaw [1]

Answer:

net work done by friction = - 2205 J

Explanation:

given,

mass of sled = 80 kg

slide down at an angle of 18°

length = 90 m

travel horizontally = 20 m before starting back up a 16° incline.

net work = ?

$h_i = initial\ height$

$h_i = L_i Sin 18^0$

$h_i = 90 sin 18^0$

$h_i = 27.81\ m$

$h_f = Final\ height$

$h_f = L_f Sin 16^0$

$h_f = 90 sin 16^0$

$h_f =24.81\ m$

net work done by friction = change in potential energy

= mg (h_f - h_i)

= (75) (9.8) (- 27.81 + 24.81)

net work done by friction = - 2205 J

7 0

3 years ago