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
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
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
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.
which property of an object is not changed by a force
