A 100 gram sample of 90 degree water causes the temperature of 100 grams of cold water to rise when the two are mixed. If the starting temperature of the cold water was 30 degrees, what will be the final temperature of the water?

The final temperature of the water : 60°C

Further explanation

Given

100 g water

t = 90 °C and 30 °C

Required

The final temperature

Solution

Q in = Q out

Q cold water = Q warm water

100 x 4.184 x (90-t)=100 x 4.184 x (t-30)

418.4(90-t)=418.4(t-30)

37656-418.4t=418.4t-12552

50208=836.8t

t = 60°C

What are the choices?

Answer: it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.explanation:   we have equation of motion ,where s is the displacement, a is the acceleration, u is the initial velocity and t is the time taken.average velocity = displacement/ time taken.average velocity = 10.69 miles/hr = 10.69*1.6*1000/(60*60) = 4.75 m/s4.75 = s/ts = 4. 1we also have acceleration = 2.18 m/s², initial velocity = 0 m/sso it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.