Hey again!
Ok..
Now... The melting Point of this solid is 90°C.
Meaning That as soon as it gets to this temp... It STARTS Melting.
So at that temp... It still has some solid parts in it.
You can say its a Solid Liquid Mixture.
Additional Heat being applied at that point is not raising the temperature;rather its used in breaking the bonds in the solid. This is the Fusion stage.
After Fusion...It'd then Be a Pure Liquid with no solids in it.
So
Q'=MC∆0----- This is the heat needed to take the solid's temp from 30°c - 90°c
Q"=ml ----- This is the heat used in breaking the bonds holding the solids in the solid-liquid phase.
So
Q= Q' + Q"
Q= mc∆0 + ml
∆0 = 90°c - 30°c = 60°c
Q= 2.5(390)(60) + (2.5)(4000)
Q=6.9 x 10⁴Joules
If you illustrate the problem, you will somewhat come up with the figure shown. The missing value is the hypotenuse of the right triangle. Using the pythagorean theorems, the value is determined to be
x = √(0.7^2 + 2.4^2)
x = 2.5 km
2.5 km is the magnitude of the distance. If you want to incorporate the displacement, the answer is reported as
2.5 km, southeast. The direction is determined from the starting point to the endpoint.
When hot tea is mixed to chilled coke, tea loses heat and coke gains heat. Thus, tea cools down but coke gets heated. Because it is liquid and liquid does not totally cool down to the ambient temperature, it and the iced drink will eventually reach the same temperature.
Let the time be t.
so,In time t , distance travelled by 1st cyclist = 12.6 t
distance travelled by 2nd cyclist = 9.2t + 0.5 (1.5) t^2
Now, cyclist 1st is already 11.4 m ahead of 2nd cyclist.
so, 9.2t + 0.5 (1.5) t^2 = 11.4 + 12.6t
find t :
t = 6.77 sec
Answer:
Explanation:
Distance travelled by Henrietta in 5.5 s = 4.15 x 5.5 = 22.825 m .
Time taken by lunch of bagels to fall vertically by 55.2 m . Let it be t .
s = ut + 1/2 g t²
55.2 = 0 + .5 x 9.8 x t²
t² = 11.26
t = 3.356 s
By the time the lunch of bagels touches the hand of Henrietta , she would have travelled further by distance
s = 3.356 x 4.15 = 13.9 m
She is now at distance of 22.825 + 13.9 = 36.725 m from window .
So lunch of bagels must travel a horizontal distance of 36.725 m in 3.356 s which the time of fall of bagel .
Speed of bagel = distance / time
= 36.725 / 3.356
= 10.94 m /s
b )
Henrietta is 36.725 m from window at the time when she catches the bangel.
