Answer:

Explanation:
The interaction of the piece of copper and water means that the first one need to transfer heat in order to reach a thermal equilibrium with water. Then:

After a quick substitution, the expanded expression is:



The final temperature of the system is:

The rock will continue to travel in a straight line with a constant velocity for ever... The reason is, once it leaves your hand there is no force acting on the rock, so it will just continue to move in a natural motion which is constant velocity.
When is at the end of the runway the velocity of the plane is given by the equation

where s=1800 m is the runway length. Thus
At half runway the velocity of the plane is

Therefore at midpoint of runway the percentage of takeoff velocity is
‰
Answer:
Q = 2.95*10^5 kJ
Explanation:
In order to calculate the energy required to melt the cooper, you first calculate the energy required to reach the boiling temperature. You use the following formula:
(1)
m: mass of cooper = 540 kg
c: specific heat of cooper = 390 J/kg°C
Tb: boiling temperature of cooper = 1080°C
T1: initial temperature of cooper = 20°C
You replace the values of the parameters in the equation (1):

Next, you calculate the energy required to melt the cooper by using the following formula:
(2)
Lf: melting constant of cooper = 134000J/kg

Finally, the total amount of energy required to melt the cooper from a temperature of 20°C is the sum of Q1 and Q2:

The total energy required is 2.95*10^5 kJ
Answer:
1848.15J
Explanation:
KE =1/2 mv^2
Mass = 60kg, velocity =40km/h =11.11m/s
Hence
KE =30 x(11.1)^2 /2 = 1848.15J