Guys solve question 46...I`ll be very thankful

PLEASE HELP QUICKLY 13 POINTS +7 FOR BEST ANSWER!!! calculate the density of an object that has a mass of 3.0 g and a volume of

raketka [301]

Density = 3/5 = 0.6g/cm^3. Since the density is less than the density of water, which is 1, the object will float.

8 0

3 years ago

Read 2 more answers

Please help fast!! I need this in less than 17 hours!

djyliett [7]

SOLUTION is given in attachment below.

7 0

3 years ago

A heat pump used to heat a house runs about one-third of the time. The house is losing heat at an average rate of 22,000 kJ/h. I

Natali5045456 [20]

The power that heat pump draws when running will be 6.55 kj/kg

A heat pump is a device that uses the refrigeration cycle to transfer thermal energy from the outside to heat a building (or a portion of a structure).

Given a heat pump used to heat a house runs about one-third of the time. The house is losing heat at an average rate of 22,000 kJ/h and if the COP of the heat pump is 2.8

We have to determine the power the heat pump draws when running.

To solve this question we have to assume that the heat pump is at steady state

Let,

Q₁ = 22000 kj/kg

COP = 2.8

Since heat pump used to heat a house runs about one-third of the time.

So,

Q₁ = 3(22000) = 66000 kj/kg

We known the formula for cop of heat pump which is as follow:

COP = Q₁/ω

2.8 = 66000 / ω

ω = 66000 / 2.8

ω = 6.66 kj/kg

Hence the power that heat pump draws when running will be 6.55 kj/kg

Learn more about heat pump here :

brainly.com/question/1042914

#SPJ4

5 0

2 years ago

A simple pendulum, 2.0 m in length, is released with a push when the support string is at an angle of 25° from the vertical. If

hammer [34]

Answer: 2.3m/s

Explanation:

mass-energy balance: ke(f) + pe(f) = ke(o) + pe(o)

since we are looking for the point at the bottom of the pendulum, thats the reference point, the lowest in the system. pe(f) is 0, since h

ke(f)=0.5m x v(f)^2

pe(f)=0

ke(o)=0.5m x v(o)^2

pe(o)-mxgxh

find h by: drawing a triangle with the pendulum at the vertical, then displaced by 25 degrees , The difference in height is h, because cos(25)=(adj)/(hyp)=(2-h)/2. I found h=0.187m

In the m-e balance, cancel the masses in all the terms.

.5xv(f)^2 =0.5v(o)^2 +gxh

Given v(o) = 1.2 m/s and g = 9.8 then v(f) = 2.2595 m/s

Therefore V(0) = 2.3 m/s

8 0

4 years ago

You and a friend each carry a 15 kg suitcase up two flights of stairs, walking at a constant speed. Take each suitcase to be the

AlekseyPX

Answer:

Both of you did the same work but you expended more power.

Explanation:

<em>Work done</em> by an object is calculated by force applied multiplied by the distance.

W=F*d

From the figure given below let us calculate force applied bith you and yopur friend.

Let us take the stairs in positive x direction,

Work done by you W₁ ,

The force applied Fₓ = F - mgsinθ =maₓ

here aₓ = 0, because both of you move with constant speed

F - mgsinθ = 0

F= mgsinθ

The work done by you on the suitcase is

W = F L cos0° , where L is he length of the staircase.

W = FL = mgsinθL , by substituting value of F

Work done by you is W₁ = mgLsinθ

Similarly work done by your friend is W₂ = mgLsinθ.

Because both of you carry suitcase of same weight and in staircase is in same angle the force applied is same .

Therefore <em>work done by both of you is same</em> . Both of you did equal work.

The power , is defined as amount of energy converted or transfered per second or rate at which work is done .

P = $\frac{W}{t}$ = $\frac{FL}{t}$

Power spend by you P₁ = mgLsinθ/t

P₁ = 15*9.8*Lsinθ/30

P₁ = 4.9L sinθ eqn 1

Power spend by your friend is P₂ = mgLsinθ/t

P₂ =15*9.8*Lsinθ/60

P₂ = 2.45Lsinθ eqn 2

Dividing eqn 1 and eqn 2

P₁ = 2P₂

You have spend more power than your friend .

Hence Both of you did equal work but you spend more power.

7 0

4 years ago