Answer:
7.82 s
Explanation:
Given:
Δy = 300 m
v₀ = 0 m/s
a = 9.8 m/s²
Find: t
Δy = v₀ t + ½ at²
(300 m) = (0 m/s) t + ½ (9.8 m/s²) t²
t = 7.82 s
Answer: D <u>(chemical</u> -> <u>heat</u> -> <u>mechanical</u>)
In automobile engines the petrol/diesel fuel enter in to the engine cylinder, due to spark at the end of the compression, fuel burnt increase the temperature and pressure, develops heat <em>(chemical energy -> heat energy). </em><em>This heat energy acts on a piston develops the work on the crankshaft </em><em>( Heat energy -> Mechanical energy)</em><em>. </em>
Kinetic Energy = 1/2mv^2
m= 1200kg
v= 24 m/s
KE = 1/2 (1200kg)(24m/s)^2 = 345,600 N
Answer : The mass of a sample of water is, 888.89 grams
Explanation :
Latent heat of vaporization : It is defined as the amount of heat energy released or absorbed when the liquid converted to vapor at atmospheric pressure at its boiling point.
Formula used :

where,
q = heat = 2000 kJ =
(1 kJ = 1000 J)
L = latent heat of vaporization of water = 
m = mass of sample of water = ?
Now put all the given values in the above formula, we get:

(1 kg = 1000 g)
Therefore, the mass of a sample of water is, 888.89 grams
Sodium and potassium are positively charged ions called cations, and chloride and phosphate form negatively charged ions called anions. is true!