Answer:
6 J
Explanation:
Gravitational Potential Energy can be calculated using the formula:
PE = mgh
where m is mass of object in <em>k</em><em>g</em>
<em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em>g is the gravitational acceleration of 10 m/s^2
h is the height at which object is thrown in <em>m</em><em>.</em>
Hence, by substituting in the values, we get:
GPE = (4.0)(10)(0.15)
<u>6</u><u> </u><u>J</u>
Hence, the potential energy is <u>6</u><u> </u><u>J</u><u>.</u>
Answer:
a) 11.2 g
b) 3.73 g.
Explanation:
a) If we assume temperature of mixture to be 100°C , heat released by steam will be 11.2 x 540 = 6048 cals and heat gain gained by will be
79 x 80 + 79 x 1 x 100 = 14220 cals . Since former heat is less than later heat ,water will not be warmed up to 100°C. Let equilibrium temperature be t .
Heat gained by water = 79 x 80 + 79 x 1 x t = 11.2 x 540 + 11.2( 100 - t )
t = 9.4°
amount of steam condensed = 11.2 g.
b) In this case, whole of water will be warmed up to 100°C as steam is much .heat required by water to warm up to boiling point
= 11.2 x 80 + 11.2 x 100 = 2016 cals
amount of steam condensed = 2016 / 540 = 3.73 g .
Answer:
Difference in height = 7.5 cm
Explanation:
We are given;.
Height of ethyl alcohol;h2 = 20 cm = 0.2 m
Density of glycerin: ρ1 = 1260 kg/m³
Density of ethyl alcohol; ρ2 = 790 kg/m³
To get the difference in height, the pressure at the top of the open end must be equal to the pressure at the point where the liquids do not mix since both points will be at different levels after the pouring.
Thus;
P1 = P2
Formula for pressure is; P = ρgh
Thus;
ρ1 × g × h1 = ρ2 × g × h2
g will cancel out to give;
ρ1 × h1 = ρ2× h2
Making h1 the subject, we have;
h1 = (ρ2× h2)/ρ1
h1 = (790 × 0.2)/1260
h1 = 0.125 m
Difference in height will be;
Δh = h2 - h1
Δh = 0.2 - 0.125
Δh = 0.075 m = 7.5 cm
A geologist is studying rock layers in an old river bed, and he finds a fossil of a fish and a horsetail rush in the same rock layer. According to the law of faunal and floral succession, the geologist can assume that the rock containing the fossils may date back as far as the <span>Devonian period</span>.
Electricity.
Solar Energy
Wind Energy
In a home, the best option as a source of energy is electricity. Though some choose to use solar energy to power their devices, electricity is more cost effective.