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4 years ago

How may stars are in the sky

Physics

2 answers:

Veseljchak [2.6K]4 years ago

7 0

Is impossible say how many stars are in the sky haha

sergeinik [125]4 years ago

4 0

It is impossible of how much stars in the sky

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Floating piece of wood - buoyancy question.?

sashaice [31]

No. because the weight is the same. no m9re water displacement

7 0

3 years ago

Which of the following could occur the net force acting on a truck is zero

Whitepunk [10]

Answer:

No net force means the truck reamains at rest or the motion of the truck does not change.

Explanation:

5 0

2 years ago

A truck is moving 14m/s to the south. If it takes the truck 20 seconds to reduce its velocity to 10m/s south. What is is acceler

WARRIOR [948]

Answer:

-0,2 m/s²

Explanation:

Acceleration = α = (V-V₀)/t

α = (10-14)/20 = -0,2 m/s²

7 0

4 years ago

A 20-car train standing on the siding is started in motion by the train’s engine. 2 cm slack is between each of the cars, which

My name is Ann [436]

Answer:

1.81 s

Explanation:

From the given information:

The links between the cars are:

1-2, 2-3, 3-4, 4-5, 5-6, 6-7, 7-8, 8-9, 9-10, 10-11, 11-12, 12-13, 13-14, 14-15, 15-16, 16-17, 17-18, 18-19, 19-20.

where;

1 denotes the first car that joins strongly attached to the engine.

There are 19 links from the above connections and each one of them has a 2 cm slack.

Thus; the total slack = 2 × 19 = 38 cm

However, the speed of the train = 21 cm/s

Then, the time taken by the pulse to travel the length of the train is expressed by using the formula:

= length / speed

= 38 / 21

= 1.81 seconds

Thus, the required time = 1.81 s

6 0

3 years ago

You hold a metal block of mass 40 kg above your head at a height of 2 m.

Kitty [74]

Answer:

The work done by gravity is 784 J.

Explanation:

Given:

Mass of the block is, $m=40\ kg$

Height to which it is raised is, $h=2\ m$

Acceleration due to gravity is, $g=9.8\ m/s^2$

Now, work done by gravity is equal to the product of force of gravity and the distance moved in the direction of gravity. So,

$\textrm{Work by gravity}=F_g\times h$

Force of gravity is given as the product of mass and acceleration due to gravity.

$\therefore F_g=mg=40\times 9.8=392\ N$ . Now,

$\textrm{Work by gravity}=F_g\times h=392\times 2=784\ J$

Therefore, the work done by gravity is 784 J.

5 0

3 years ago