1. A kettle contains 1.5kg of water at a
temperature of 18°C. How much energy is
needed to bring the water to the boil?

Answer:

(a) 3.06 s

(b) 45.92 m

(c) 6.12 s

(ch) 1.43 s

Explanation:

Vertical Launch Upwards

In a vertical launch upwards, an object is launched vertically up without taking into consideration any kind of friction with the air.

If vo is the initial speed and g is the acceleration of gravity, the maximum height reached by the object is given by:

[tex]\displaystyle h_m=\frac{v_o^2}{2g}[/tex]

Similarly, the time it needs to reach the maximum height is:

[tex]\displaystyle t_m=\frac{v_o}{g}[/tex]

The object's speed (vf) after time t is:

[tex]v_f=v_o-g.t[/tex]

The baseball is thrown up at vo=30 m/s.

(a) It's required to calculate the time it needs to reach the maximum height:

[tex]\displaystyle t_m=\frac{30}{9.8}=3.06[/tex]

[tex]t_m=3.06~s[/tex]

(b) The maximum height is:

[tex]\displaystyle h_m=\frac{30^2}{2(9.8)}=45.92[/tex]

[tex]h_m=45.92~m[/tex]

(c) The time needed to travel up is the same time required to return to the starting point:

[tex]t_f=2*t_m=2*3.06[/tex]

[tex]t_f=6.12~s[/tex]

(ch) The speed will be vf=16 m/s at a certain time. Using the equation

[tex]v_f=v_o-g.t[/tex]

We solve for t:

[tex]\displaystyle t=\frac{v_f-v_o}{g}[/tex]

[tex]\displaystyle t=\frac{30-16}{9.8}[/tex]

t = 1.43 s

Answer:The answer is circular orbits I hope this helps

Explanation:

Answer: it is turned into thermal energy

C. it is transformed into thermal energy

Answer:

F = 5.9 N

Explanation:

Given that,

Mass of water, m₁ = 1000 kg

Mass of the Sun, [tex]m_2=1.99\times 10^{30}\ kg[/tex]

Distance between two bodies, [tex]r=1.5\times 10^{11}\ m[/tex]

We need to find the force of gravity between water and the Sun. The formula for the gravitational force between two bodies is given by :

[tex]F=G\dfrac{m_1m_2}{r^2}\\\\F=6.67\times 10^{-11}\times \dfrac{1000\times 1.99\times 10^{30}}{(1.5\times 10^{11})^2}\\\\F=5.89\ N[/tex]

or

F = 5.9 N

Hence, the correct option is (b).

Answer:

1=false and 2=1st answer is correct

jsjshebsjsusunxndj 78

Answer:

D. A difference in resistance

Answer:

5m/s²

Explanation:

Given parameters:

Mass of wagon  = 10kg

Force of pull  = 70N

Frictional force = 20N

Unknown:

Acceleration of the wagon = ?

Solution:

Frictional force is a force that opposes motion.

The net force is given as:

   Net force  = mass x acceleration

 Force of pull  - Frictional force = mass x acceleration

 Insert the parameters and solve;

     70 - 20  = 10 x acceleration

       50  = 10 x acceleration

      Acceleration  = 5m/s²

Answer:

acceleration will be twice as much

Answer:

Oppenheimer suggested that the bomb laboratory operate secretly in an isolated area but allow free exchange of ideas among the scientists on the staff.

Explanation:

Answer:

π/2 radians.

Explanation:

Angular Displacement

It's the angle expressed in radians, degrees, revolutions, etc. through which a point revolves around a point called the center.

To find the angular displacement, we must recall a full revolution, or turn around the center measures 360 degrees, or 2π radians.

The Earth completes a turn every 24 hours. This means that in 6 hours, it has given 6/24 = 1/4 of a turn.

This means that, measured in radians, the angular displacement of a person during 6 hours is:

1/4*2π radians

Simplifying:

π/2 radians.

Answer:

0.13m/s

Explanation:

jhghffhjffhjfhjfhjf

Explanation:

mass=50g

velocity=42cm/s

Kinetic energy

As we know that

[tex]{\boxed{\sf kinetic\:energy={\dfrac {1}{2}}mv^2}}[/tex]

[tex]{:}\longrightarrow[/tex][tex]\sf k.v={\dfrac {1}{{\cancel{2}}}}\times 50\times {\cancel{42}}^2 [/tex]

[tex]{:}\longrightarrow[/tex][tex]\sf k.v=50\times 21^2 [/tex]

[tex]{:}\longrightarrow[/tex][tex]\sf k.v=50×441 [/tex]

[tex]{:}\longrightarrow[/tex][tex]\sf k.v=22050MJ [/tex]

[tex]\therefore[/tex][tex]{\underline{\boxed{\bf Kinetic\:energy=22Joule}}}[/tex]

Answer:

nitric acid

Explanation:

because it is a solvent

Answer:

acetic acid

Explanation:

Not sure but I think so :) hope its right and helps

Answer:

Hi. U should do like this

Answer:

3.335641 nanoseconds for meters

Answer:

The force must increase

Explanation:

According to newton's second law "force is the product of mass and acceleration".

      Force  = mass  x acceleration

Now, the mass of the sports car is lesser compared to that of the truck. Therefore, to take both automobiles to the same speed, enough force must be applied by the engine of the truck.

There must be an increase in the force in order to make both automobiles attain the same speed.

Answer:

Explanation:

(b) The initial velocity is added to that due to acceleration by gravity. The velocity is increased linearly by gravity at the rate of 9.8 m/s². The average velocity of the pebble will be its velocity halfway through the 2-second time period.* That is, it will be ...

  4 m/s + (9.8 m/s²)(2 s)/2 = 13.8 m/s . . . . average velocity

__

(a) The distance covered in 2 seconds at an average velocity of 13.8 m/s is ...

  d = vt

  d = (13.8 m/s)(2 s) = 27.6 m

The water is about 27.6 m below ground.

_____

* We have chosen to make use of the fact that the velocity curve is linear, so the average velocity is half the sum of initial and final velocities:

  vAvg = (vInit + vFinal)/2 = (vInit + (vInit +at))/2 = vInit +at/2

__

If you work this in a straightforward way, you would find distance as the integral of velocity, then find average velocity from the distance and time.

  [tex]\displaystyle d=\int_0^t{(v_0+at)}\,dt=v_0t+\dfrac{1}{2}at^2=t\left(v_0+a\dfrac{t}{2}\right)\\\\v_{avg}=\dfrac{d}{t}=v_0+a\dfrac{t}{2}\qquad\text{the formula we started with}[/tex]

Answer:

The kinetic coefficient of friction of the sled on the snow is 0.05

Explanation:

The given parameters are;

The weight of the sled Jill is pulling, W = 200 N

The force with which Jill is pulling the the sled = 10 Newtons

The nature of the speed with which the sled is pulled = Constant speed

Therefore, given that the only opposing force to the pulling of the sled = The force of kinetic friction, we have;

The force with which Jill is pulling the the sled = 10 Newtons = The force of kinetic friction, [tex]F_k[/tex]

The force of kinetic friction = The weight of the sled, W × The kinetic coefficient of friction of the sled on the snow, [tex]\mu _k[/tex]

[tex]F_k[/tex] = W × [tex]\mu _k[/tex]

[tex]\mu _k[/tex] = [tex]F_k[/tex]/W = 10 N/(200 N) = 0.05

The kinetic coefficient of friction of the sled on the snow = [tex]\mu _k[/tex] = 0.05.

Answer:

d

Explanation:

it is never stated in science

Objects of the same size will accelerate equally if they have different forces applied to them. This statement (D) does NOT apply to Newton’s second Law of Motion.

Newton’s second law of motion states that “Force is equal to the rate of change of momentum. For a constant mass, force equals mass times acceleration.

As momentum is product of mass and velocity, the more mass something has, the more force it would take to accelerate it.  So option (A) is correct.

As rate of change of momentum of a body refers product of mass and acceleration of a body,  the more force applied to an object’s mass, the more it will accelerate and the force required to accelerate an object equals the objects mass times it’s acceleration. So, option (B) and (C) is correct.

But  force has no direct elation with size of the body. So, option (D) is not correct.

Learn more about Newton's second law of motion here:

https://brainly.com/question/13447525

#SPJ2

Answer:

producer

Explanation:

grass is producing

by photosynthesis

Answer: 40 N

Explanation: Use the formula

F = m a

to solve this.

F = (8 kg) (5 m/s²)

F = 40 kgm/s²

F = 40 N

The given value are:

Acceleration,

Mass,

The force will be:

→ [tex]Force (F) = Mass(m)\times Acceleration (a)[/tex]

By substituting the values, we get

                   [tex]= 5\times 8[/tex]

                   [tex]= 40 \ N[/tex]

Thus the response above is right.

Learn more about force here:

https://brainly.com/question/12800231

Answer:it’s the graph starts on the origin but is going down

Explanation: khan academy