Recent content by studenta

This is what i did: Q for iron = mc(tf-ti) = 2.50 x 10^2 kg x 450 J/kg/°c x (10°c - 35°c) = -2.813 x 10^6 J Q for water = 4.4 x10^6 J - 2.813 x 10^6 J = 1.587 x10^6 J mass for water = Q / c x (tf-ti) = 1.587 x10^6 J / 4180 x (...

A 2.50 x 10^2 kg iron car engine contains water as coolant. Suppose the temperature of engine is 35 degree celcius when it shut off and air temperature is 10degree celcius. The heat given off by engine and watering it as they cool to air temperature is 4.4 x10^6 J. What is the mass of water used...

Thanks. What about the 3rd questions? Should we determine sig.figs according to questions?

SO 2.1 × 10^2 m is the correct answer instead of 208 m? right?

1) Which is right? 65m/s x 3.2 s = 208 m or 65m/s x 3.2 s = 2.1 x 10^1 m2) is 210 - 3 s.f. or 2 s.f. ? 3) my teacher uses the question as a guide for s.f., is that correct? e.g. A projectile is fired with an initial speed of 1.12 s at a...