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2 years ago

Use Newton’s first law to explain why a book on a desk does not move

Physics

2 answers:

aleksley [76]2 years ago

6 0

Answer:

The book does not move because all the forces acting on the book are in equilibrium, creating a net force of zero magnitude on the book. Since the net force on the book is zero, this means that the book will remain in its present state of motion (which is that the book is motionless).

Explanation:

Newton's first law states that all body will remain in their present state of motion unless acted upon by an external force. In order word, a moving body should continue moving forever, and a body at rest should remain like that forever, unless they are acted upon by a force to either cause them to stop stop or to start moving respectively.

rewona [7]2 years ago

5 0

Answer:

nothing moves if anything other doesn't move it.

natural position of things is the resting

Explanation:

yeah that's it

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Three plant like organisms which cannot produce their own food are

SpyIntel [72]

I can only offer you one which is mushroom. They're fungus' and they can't produce their own food. They get their food from decaying and dead animals and absorb it through their roots.

8 0

3 years ago

A 500 kg sack of coal falls vertically onto a 2000 kg railroad flatcar which was initially moving horizontally at 3 m/s. no exte

Zinaida [17]

Since there are no external forces, including friction, act on the flatcar. after the sack rests on the flatcar, we would assume that momentum is conserved. This means that

total momentum of car before collision = total momentum of car after collision.

Recall,

momentum = mass x velocity

From the information given,

mass of car before collision = 2000

velocity of car before collision = 3

Thus,

total momentum of car before collision = 2000 x 3 = 6000

Also,

mass of sack = 500

mass of car and sack after collision = 500 + 2000 = 2500

velocity after collision = v

momentum after collision = 2500 x v = 2500v

Since momentum is conserved, then

6000 = 2500v

v = 6000/2500

v = 2.4

the speed of the flatcar is 2.4 m/s

6 0

1 year ago

Suppose I have a vector that is 7 units long and that makes an angle of +30 degrees from the positive x-axis. I want to add to t

Vinil7 [7]

Answer:

sum of these two vectors is 6.06i+3.5j-3.5i+6.06j = 2.56i+9.56j

Explanation:

We have given first vector which has length of 7 units and makes an angle of 30° with positive x-axis

So x component of the vector $=7cos30^{\circ}=7\times 0.866=6.06$

y component of the vector $=7sin30^{\circ}=7\times 0.5=3.5$

So vector will be 6.06i+3.5j

Now other vector of length of 7 units and makes an angle of 120° with positive x-axis

So x component of vector $=7cos120^{\circ}=7\times -0.5=-3.5i$

y component of the vector $=7sin120^{\circ}=7\times 0.866=6.06j$

Now sum of these two vectors is 6.06i+3.5j-3.5i+6.06j = 2.56i+9.56j

5 0

3 years ago

Two stars have the same radius but have very different temperatures. the red star has a surface temperature of 3,000 k and the b

dangina [55]

I would say that insofar as the two stars temperatures are presumably closely related to their luminosity, that the blue star at 156,100 k compared to 3000k for the red star then the blue star has a luminosity of 52 times that of the red star.

4 0

3 years ago

A stone takes 5.4 seconds to fall from the top of a cliff. The cliff is

Allushta [10]

Answer:

143

Explanation:

Using one of the 3 fundamental equations in physics, y=vo*t+1/2gt^2, we can use this equation to find the total distance that was traveled.

Acceleration due to gravity is always 9.8m/s^2 and time is 5.4s, we also have no initial velocity.

Given this, we can plug in the known variables.

y=0t+1/2*9.8*5^2

simplify,

y=4.9*5.4^2

y=4.9*29.16

y=142.884m which we can round up to 143 meters

Final Answer: 143 meters

4 0

2 years ago