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2 years ago

Hi guys help me plss

Physics

1 answer:

Orlov [11]2 years ago

7 0

Answer:

1. the branch of science concerned with the nature and properties of matter and energy. The subject matter of physics includes mechanics, heat, light and other radiation, sound, electricity, magnetism, and the structure of atoms

2. We use physics in our daily life activities such as walking, cutting, watching, cooking, and opening and closing things.

Physics is one of the most elementary sciences that contributes directly to the development of science and the development of new technologies

3. Isaac Newton: the first physicist. Isaac Newton is popularly remembered as the man who saw an apple fall from a tree, and was inspired to invent the theory of gravity.

4. Newton's laws of motion relate an object's motion to the forces acting on it. In the first law, an object will not change its motion unless a force acts on it. In the second law, the force on an object is equal to its mass times its acceleration. In the third law, when two objects interact, they apply forces to each other of equal magnitude and opposite direction.

Explanation:

You might be interested in

Classify the following situations as involving balanced or unbalanced forces.

tester [92]

Answer:

1) Unbalanced

2) Balance

3) Balanced

4) Unbalanced

5) Unbalanced

Explanation:

For 1 and 5, since the objects are not at a constant speed/velocity, their forces must be unbalanced.

For 2 and 3, their speeds are constant so that means the force is balanced. If the bycicle or box started accelerating, that would indicate an unbalanced force

For 4, the speed is constant, but it's direction is not indicating another unbalanced outside force causing it to turn. The force is unbalanced.

5 0

3 years ago

A truck, initially at rest, rolls down a frictionless hill and attains a speed of 20 m/s at the bottom. To achieve a speed of 40

Crank

Answer:

To achieve the velocity of 40 m/sec height will become 4 times

Explanation:

We have given initially truck is at rest and attains a speed of 20 m/sec

Let the mass of the truck is m

At the top of the hill potential energy is mgh and kinetic energy is $\frac{1}{2}mv^2$

So total energy at the top of the hill $=mgh+0=mgh$

At the bottom of the hill kinetic energy is equal to $\frac{1}{2}mv^2$ and potential energy will be 0

So total energy at the bottom of the hill is equal to $0+\frac{1}{2}mv^2$

Form energy conservation $mgh=\frac{1}{2}mv^2$

$v=\sqrt{2gh}$ , for v = 20 m/sec

$20=\sqrt{2\times 9.8\times h}$

Squaring both side

$19.6h=400$

h = 20.408 m

Now if velocity is 0 m/sec

$40=\sqrt{2gh}$

$19.6h=1600$

h = 81.63 m

So we can see that to achieve the velocity of 40 m/sec height will become 4 times

5 0

3 years ago

A particle moves with acceleration function a(t) = 5 + 4t - 2t^2. Its initial velocity v(0) = 3 m/s and its initial displacement

eimsori [14]

Answer:

Its position after 4 seconds is 62 meters.

Explanation:

It is given that,

The acceleration of the particle is given by equation :

$a(t)=5+4t-2t^2$

Also, $a=\dfrac{dv}{dt}$

$v=\int\limits {a.dt}$

$v=\int\limits {(5+4t-2t^2).dt}$

$v=5t+2t^2-\dfrac{2}{3}t^3+c$

At t = 0, $v(0)=3\ m/s$ . So, c = 3

$v=5t+2t^2-\dfrac{2}{3}t^3+3$

Also, $v=\dfrac{ds}{dt}$ , s is the position

$s=\int\limits {v.dt}$

$s=\int\limits {(5t+2t^2-\dfrac{2}{3}t^3+3).dt}$

$s=\dfrac{5}{2}t^2+\dfrac{2}{3}t^3-\dfrac{t^4}{6}+3t+c'$

At t = 0, $s(0)=10\ m$ . So, c' = 10

$s=\dfrac{5}{2}t^2+\dfrac{2}{3}t^3-\dfrac{t^4}{6}+3t+10$

At t = 4 s

$s=\dfrac{5}{2}(4)^2+\dfrac{2}{3}(4)^3-\dfrac{(4)^4}{6}+3(4)+10$

s = 62 m

So, at t = 4 seconds the position of the particle is 62 meters. Hence, this is the required solution.

5 0

3 years ago

The magnet below is cut in half. what will be the result?

loris [4]

Answer:

the correct would be c

Explanation:

a magnet will always have a north and a south so if you cut the magnet in half the north part would have a south on the opposite end and vice versa .

3 0

3 years ago

The sun is the ___________ of all the energy that moves though food

Marta_Voda [28]

The sun is the <em><u>source</u></em> of all the energy that moves through food. It helps the plants to grow which in turn become food that we and other animals eat.

Hope it helps :)

3 0

4 years ago

Read 2 more answers