what is it? and explain pls

Answer:

Explanation:

What is the first law of thermodynamics?

"The first law of thermodynamics state that energy is conserved"

the expression bellow is the  Change in internal energy of a system

Change in internal energy of a system

= heat put into the system - work done by the system on its surroundings,

or

ΔU = ΔQ - ΔW.

given data

Work done=125J

Heat= 75J

change=?

Substituting we have

ΔU = 75- 125

ΔU = -50J

"ΔQ is positive if heat flows into the system, negative if it flows out of the system.

ΔW is positive if the system does work on its surroundings and it is negative if work is done on the system. "

Answer:

D

Explanation:

Answer:

Hydroelectric power plants

Explanation:

This is because hydropower is a form of renewable energy that uses water stored in dams, rivers to create electricity

Answer:

Explanation:

See attachment

Answer:

a = - 1 [m/s²]

Explanation:

To solve this problem we must use the following equation of kinematics.

[tex]v_{f} = v_{o} +(a*t)[/tex]

where:

Vf = final velocity = 0 (velocity at 10 seconds)

Vo = initial velocity = 4 [m/s]

a = desacceleration [m/s²]

t = time = 4 [s]

From the graph, we can deduce that between the second 10 and the second 6 there are (10-6) = 4 seconds difference.

In the second 6, the velocity is 4 [m/s]

0 = 4 + (a*4)

4*a = -4

a = - 1 [m/s²]

Answer:

The breaking strength of the string is 717.19 N

Explanation:

Given;

initial tension on the string, T₁ = 53.9 N

initial radius of the string, r₁ = 2.59 m

initial speed of the rock, v₁ = 21.8 m/s

final radius of the string, r₂ = 1.23 m

final speed of the rock, v₂ = 54.8 m/s

the final tension on the string = breaking strength, T₂ = ?

Apply centripetal force equation due to inward motion;

[tex]T= \frac{mv^2}{r}\\\\Tr = mv^2\\\\m =\frac{Tr}{v^2}\\\\ \frac{T_1r_1}{v_1^2} = \frac{T_2r_2}{v_2^2}\\\\T_2 = \frac{T_1r_1v_2^2}{r_2v_1^2}\\\\ T_2 = \frac{(53.9)(2.59)(54.8)^2}{(1.23)(21.8)^2}\\\\ T_2 = 717.19 \ N[/tex]

Therefore, the breaking strength of the string is 717.19 N

Answer:

2.31m/s² downwards

Explanation:

The sum of forces on the object is expressed as;

T-W

T is the tension on the rope

W is the weight

According yo Newton's second law:

T-W= ma

m is the mass

a is the acceleration

Given

T = 75N

W = mg = 10×9.81

W = 98.1N

Substitute

75-98.1 = 10a

-23.1 = 10a

a = -23.1/10

a = -2.31m/s²

The magnitude of the acceleration is 2.31m/s² and directions is downwards

Answer:

U

Explanation:

Answer:

Explanation:

According to law of conservation of momentum

(m1+m2)v = m1u1+m2u2

Let m1 and m2 be the masses

u1 and u2 be their respective velocities

v is the velocity of combined objects

Given

m1 =60kg

m2 = 40kg

v =0 m/s

u2 -  u1 = 60 ............ 1

0 = 60u1 + 40u2 = 0 .......... 2

From 1: u2 = 60+u1

Substitute into 2:

60u1 + 40(60+u1) = 0

60u1 +2400 +40u1 = 0

100u1 = -2400

u1 = -2400/100

u1 = -24m/s

Hence the speed of the 60 kg mass is 24m/s (in the negative direction)

Answer:

Different ions are deflected by the magnetic field by different amounts. The amount of deflection depends on: the mass of the ion. Lighter ions are deflected more than heavier ones.

Answer: Height = 0.45m

Explanation:

According to the conservation of energy, When there are no interactions outside a system ie  neglecting air resistance,The change in kinetic energy is equal to the change in potential energy in a closed system.

Therefore the kinetic energy decrease, the potential energy increases, and  decreases for increase in Kinetic energy

an is represented by the formulae

ΔKinetic energy + ΔPotential energy = 0

ΔKinetic energy = -ΔPotential energy ( where negative sign represent decrease as kinetic energy increases.

ΔK.E=ΔP.E

420J- 220J= mgh

mass = 45kg

g =gravitational acceleration =9.8 m/s^2

200J = 45 X 9.8 X h

h = 200/45 x 9.8 /= 0.45m

Answer:

3 m/s

Explanation:

We can solve with kinematics or with energy.

Using kinematics, and taking down to be positive, we're given:

Δy = 0.45 m

v₀ = 0 m/s

a = 10 m/s²

Find: v

v² = v₀² + 2aΔy

v² = (0 m/s)² + 2 (10 m/s²) (0.45 m)

v = 3 m/s

Or, we can use energy.

PE = KE

mgh = ½ mv²

v = √(2gh)

v = √(2 × 10 m/s² × 0.45 m)

v = 3 m/s

Answer:

Cccccccc GIVE BRAINLYEST PLEASE

Answer: It´s c-skeletal

Explanation:

Answer:

117

Explanation:

Answer:

The acceleration on an object due to the gravity of any massive body is represented by g (small g). The force of attraction between any two unit masses separated by unit distance is called universal gravitational constant denoted by G(capital g). The relation between G and g is not proportional.

Explanation:

Answer: 5000J

Explanation:

equation for kinetic energy is k=(mv^2)/2

plug in your mass and velocity

k = (2000*5^2)/2 = 5000J

Answer:

Explanation:

it is C

Answer:

b

Explanation:

bcuz I looked it up and it was on there

Answer:

the answers are:

- cool fluid sinks

- warm fluid rises

- convention current

Explanation:

Im late but mark me as brainliest for helping you out cause the one on top is clueless

Answer:

The time required is t = 9.39 [s]

Explanation:

To solve this problem we must use the following equation of kinematics.

[tex]v_{f}=v_{o} +(a*t)[/tex]

where:

Vf = final velocity = 77 [m/s]

Vo = initial velocity = 0

a = acceleration = 8.2 [m/s²]

t = time [s]

The initial speed is zero, since the airplane begins its movement from rest. The initial speed is zero, since the aircraft begins its movement from rest. Another important fact is that the sign of acceleration is positive since the plane is accelerating, that is, its speed is increasing.

Now replacing:

77 = 0 + (8.2*t)

t = 9.39 [s]

Answer:

u = 0.334 m/s

Explanation:

The formula for Reynold's number is given as follows:

Re = ρuL/μ

where,

Re = Reynold's Number = 2511

ρ = Density of air = 1.25 kg/m³

μ = Dynamic Viscosity of Air = 1.83 x 10⁻⁵ Pa.s

L = Characteristic Length = Diameter of Sphere = 11 cm = 0.11 m

u = Speed = ?

Therefore,

2511 = (1.25 kg/m³)(u)(0.11 m)/(1.83 x 10⁻⁵ Pa.s)

u = (2511)/(7513.66 s/m)

u = 0.334 m/s

Answer:

Explanation:

weight of the car mg = m g

frictional force acting on the car = μ mg where μ is coefficient of friction

= m μ g

This force provides centripetal force , hence

m μ g  = m v² / R

μ = v² / rg

= 22 x 22 / 65 x 9.8

= .759  

Answer:

The speed of the ball is 7.36 m/s

Explanation:

Constant Acceleration Motion

It happens when the velocity of an object changes by an equal amount in every equal period of time.

Being a the constant acceleration, vo the initial speed, vf the final speed, and t the time, the following relation applies:

[tex]v_f=v_o+at[/tex]

Since the situation corresponds to a vertical motion, the acceleration is g=9.8 m/s^2.

The ball is thrown downward at vo=0.5 m/s. Its speed at t=0.7 seconds is

[tex]v_f=0.5+9.8\cdot 0.7[/tex]

[tex]v_f=7.36\ m/s[/tex]

The speed of the ball is 7.36 m/s

Note: There is no use of the height it was released from

Answer:

The value is [tex]v = 7.89 \ m/s[/tex]

Explanation:

From the question we are told that

  The mass  of the object is [tex]m = 0.414 \ kg[/tex]

   The force is [tex]F = 2.08 \ N[/tex]

  The time taken is  [tex]t = 1.57 \ s[/tex]

Generally the force acting on the object according to Newton's second law is

        [tex]F = \frac{ m (v -u )}{t}[/tex]

=>     [tex]v = \frac{F * t}{m} + u[/tex]

Here u is the initial velocity with value  0 m/s since the object was initially at rest

        [tex]v = \frac{2.08 * .57}{0.414 } + 0[/tex]

     [tex]v = 7.89 \ m/s[/tex]

Answer:

True

Explanation:

Answer:

K = 567.91 J

Explanation:

Given that,

Mass of sphere, m = 18 kg

Radius of a sphere, r = 0.8 m

It makes one complete revolution every 0.4 s.

The speed of center of mass of the sphere is 8 m/s

We need to find the rotational kinetic energy of the sphere. It is given by the formula as follows :

[tex]K=\dfrac{1}{2}I\omega^2[/tex]

I is moment of inertia,

[tex]I=\dfrac{2}{5}mr^2\\\\I=\dfrac{2}{5}\times 18\times (0.8)^2\\\\I=4.608\ kg-m^2[/tex]

[tex]\omega[/tex] is angular speed

[tex]\omega=\dfrac{2\pi }{0.4}\\\\=15.7\ rad/s[/tex]

So,

[tex]K=\dfrac{1}{2}\times 4.608\times (15.7)^2\\\\K=567.91\ J[/tex]

So, the rotational kinetic energy of the sphere is 567.91 J.

The rotational kinetic energy of the sphere is 710.8 J.

I = ¹/₂mr²

I = 0.5 x 18 x (0.8)²

I = 5.76 kgm²

ω = 2πf

ω = 2π x (1/0.4s)

ω = 15.71 rad/s

K.E = ¹/₂Iω²

K.E = 0.5 x (5.76) x (15.71)²

K.E = 710.8 J

Thus, the rotational kinetic energy of the sphere is 710.8 J.

Learn more about rotational kinetic energy here: https://brainly.com/question/25803184

Answer:

F = 240 N

Explanation:

Let the mass of the puck, m = 160 g = 0.16 kg

Initial speed, u = 0 (at rest)

Final speed, v = 5 m/s

Time, t = 0.03 s

We need to find the average force on the hockey puck while it is in contact with the stick. Force is given by the formula as follows :

F = ma, a is acceleration

[tex]F=\dfrac{m(v-u)}{t}\\\\F=\dfrac{0.16\times (45-0)}{0.03}\\\\F=240\ N[/tex]

So, the average force is 240 N.

Answer:

my answer is in explanation below

Explanation:

You would convince him by saying the pattern adds elevation to the shoe therefore causing more friction.

(If it's wrong, I am sorry, I'm not in college)

(If it's right, can I get that brainliest?)

Answer:

Air resistance

Explanation:

Air resistance encountered as the person falls

Answer:

the location where potential energy is zero

Explanation:

Answer:

Explanation:

Force F = GMm / R²

mass of the sun M = 1.99 x 10³⁰ kg

mass of the earth = 5.97 x 10²⁴ kg

value of G = 6.67 x 10⁻¹¹

for perihelion point R = 1.48 x 10¹¹ m

Force = 6.67 x 10⁻¹¹ x  1.99 x 10³⁰ x 5.97 x 10²⁴ / ( 1.48 x 10¹¹ )²

= 36.17 x 10²¹ N  

for aphelion point R = 1.52 x 10¹¹ m

Force = 6.67 x 10⁻¹¹ x  1.99 x 10³⁰ x 5.97 x 10²⁴ / ( 1.52 x 10¹¹ )²

= 34.29  x 10²¹ N