Answer:
12445 J
Explanation:
Given that
Power output, P = 5 kW
efficiency of the engine, e = 27% = 0.27
Thermal energy expelled, Q(c) = 9085 J
Heat absorbed, Q(h) = ?
Using the formula
e = W/Q(h)
e = [Q(h) - Q(c)] / Q(h)
e = 1 - Q(c)/Q(h)
Now, substituting the values into the formula, we have
0.27 = 1 - 9085/Q(h)
9085/Q(h) = 1 - 0.27
9085/Q(h) = 0.73
Q(h) = 9085 / 0.73
Q(h) = 12445 J
Thus, the heat absorbed is 12445 J
what is mean by combination reaction ?
[tex] \underline{\purple{\large \sf Combination \: reaction :-}} [/tex]
Those reaction in which two or more substances combine to form a one new substance are called Combination reaction
In this reaction, We can add :
Two or more elements can combine to form a compound.Two or more compounds can combine to from a one new compound.An element and a compound can combine to form a new compound.[tex] \underline{\green{\large \sf For\: example :}} [/tex]
[tex] \sf 2H_{2} + O_{2} \: \underrightarrow{Combination} \: 2H_{2}o[/tex]
In this, Hydrogen is an element and Oxygen is another element. Both are combined to form compound 'Hydrogen oxide'. Hydrogen oxide is commonly known as water.
A 96 kg man lying on a surface of negligible friction shoves a 75 g stone away from himself, giving it a speed of 7.2 m/s. What speed does the man acquire as a result?
Answer:
7.21m/s
Explanation:
Using the law of conservation of momentum expressed as;
m1u1 + m2u2 = (m1+m2)v
m1 and m2 are the mass of the man and the stone respectively
u1 and u2 are their respective initial velocities
v is their final common velocity
Given
m1 = 96kg
m2 = 75g = 0.075kg
u1 = ?
u2 = 0m/s (initial speed of the stone)
v = 7.2m/s
Substitute into the firmula and get u1
96u1 + 0.075(0) = (96 + 0.075)(7.2)
96u1 = 96.075(7.2)
u1 = 691.74/96
u1 = 7.21m/s
Hence the man acquired a speed of 7.21m/s
A car starts from point A, goes 100 km to point B, immediately turns around, and returns to point A. The round trip takes 4 hours.
What is the average speed of the car?
Answer:
50 km/h
Explanation:
200 km = 4 hours
200/4=50
50km/h
which property of an object is not changed by a force
