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Sunny_sXe [5.5K]
3 years ago
14

If a 4.5 kg object is dropped from a height of 6.0 m, what will be its velocity when it is halfway toward the ground? (Use g = 9

.80 m/s2, and ignore air resistance.) 7.7 m/s 11 m/s 16 m/s 29 m/s
Physics
2 answers:
dangina [55]3 years ago
7 0
When an object falls or is dropped from rest it's initial velocity is zero.
Using the equations for a motion in straight line. I can find the time it takes to reach 3.0 m down (half way).
x = vt - 4.9t²
-3 = 0 - 4.9t²
-3/-4.9 = t²
0.6122 = t²
0.7825 sec = t

v = v - gt
v = 0 - 9.8(0.7825)
v = -7.67 m/s
the negative denotes downward direction.

You  could also solve the problem using potential and kinetic energy.

Since it starts with maximum PE and gets converted to KE when it hits the ground. mgh = mv²/2
mass cancels, use 3 meters for the halfway distance
-9.8(-3) = v²/2
29.4 * 2 = v²
√(58.8) = 7.67 m/s downwards
notsponge [240]3 years ago
6 0

Answer:

7.7 rounded

Explanation:

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suppose 384g of steam originally at 100C is quickly cooled to produce liquid water at 31C. How much heat must be removed from th
dlinn [17]

Answer:

Q=977216.256\ J=977.216\ kJ

Explanation:

Given:

  • mass of  steam, m=384\ g
  • temperature of steam, T_{is}=100^{\circ}C
  • temperature of resultant water, T_{fw}=31^{\circ}C

We have,

  • latent heat of vapourization of water, L=2256\ J.g^{-1}
  • specific heat capacity of water, c=4.186\ J.g^{-1}

<em>When we cool the steam of 100°C then firstly it loses its latent heat to convert into water of 100°C and the further cools the water.</em>

<u>Now the heat removed from steam to achieve the final state of water:</u>

\rm Q=latent\ heat\ of\ vapourization+sensible\ heat\ of\ water

Q=m(L+c.\Delta T)

Q=384(2256+4.186\times (100-31))

Q=977216.256\ J=977.216\ kJ

3 0
3 years ago
Describe the three major layers of the earth including temperature thickness of chemical composition
Elena L [17]
The three main layers are the core, the mantle, and the crust. The core is divided into two parts, the liquid outer core, and the solid inner core. Together it is 3450 km thick. The mantle is 2100 km thick, and the crust is 35-70 km thick. Hope I helped!
3 0
3 years ago
Select the appropriate units for each property of a wave.
IceJOKER [234]

Intensity: Decibels

Amplitude: Meters

Frequency: Hertz

<u>Explanation:</u>

The Wave is not visible to eyes and they can easily propagate through vacuum. the average power travelling at a given period of time in a space is the intensity. Decibels is the measure of intensity. it is measured in the decibel scale. The wave's strength and the intensity gives the amplitude of wave. It is measured using meters.

The wave's amplitude and the energy has a direct proportionality.  The number occurrence of wave cycles per second refers to the frequency of wave. it is measured in hertz. it is also measured as the number of cycles that occurs per second.

4 0
3 years ago
If a reaction is exothermic, then which of the following statements is always true? If a reaction is exothermic, then which of t
sesenic [268]

Explanation:

Reactants ⇒ product + heat (exothermic reaction) ....(1)

We have given that the reaction is exothermic, so the heat is rejected from the reaction. We know that heat is the form of energy.

From equation (1)

from the given equation we can see that reactants have more energy than products.

So the reactants have higher potential energy in comparison to the products.

7 0
3 years ago
A lad, waiting for his friend walks in the sidewalk, in front of her house, from the front door, first, he moves towards the Pos
Andreas93 [3]

His total displacement from his original position is -1 m

We know that total displacement of an object from a position x to a position x', d = final position - initial position.

d = x' - x

If we assume the lad's initial position in front of her house is x = 0 m. The lad then moves towards the positive x-axis, 5 m. He then ends up at x' = 5 m. He then finally goes back 6 m.

Since displacement = final position - initial position, and his displacement is d' = -6 m (since he moves in the negative x - direction or moves back) from his initial position of x' = 5 m.

His final position, x" after moving back 6 m is gotten from

x" - x' = -6 m

x" = -6 + x'

x" = -6 + 5

x" = -1 m

Thus, his total displacement from his original position is

d = final position - initial position

d = x" - x

d = -1 m - 0 m

d = -1 m

So, his total displacement from his original position is -1 m

Learn more about displacement here:

brainly.com/question/17587058

3 0
3 years ago
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