Answer:
1.11 m/s
Explanation:
The motion of the boat is an example of accelerated motion, since the velocity is not constant. However, we don't need to find the acceleration, because we are only interested in the average velocity of the boat, which is given by:
where d is the total distance covered and t the time taken. In this problem, the boat covered a distance of d = 20 m and it takes t = 18 s, therefore the average velocity is
Answer;
The temperature change for the second pan will be lower compared to the temperature change of the first pan
Explanation;
-The quantity of heat is given by multiplying mass by specific heat and by temperature change.
That is; Q = mcΔT
This means; the quantity of heat depends on the mass, specific heat capacity of a substance and also the change in temperature.
-Maintaining the same quantity of heat, with another pan of the same mass and greater specific heat capacity would mean that the change in temperature would be much less lower.
Here as we know that there is no loss of energy
so we can say that maximum kinetic energy will become gravitational potential energy at its maximum height
So here we have
here we have
v = 20 m/s
m = 8000 kg
now from above equation we have
so maximum height is 20.4 m
Coal is burned to get energy. By burning coal, green houses gases like carbon dioxide, nitrogen oxides and suphur oxides are produced.
Rest of the energy sources given in the option are clean energies.
Answer is A.
The answer is 2.49 x 10^5 KJ. This was obtained (1) use the formula for specific heat to achieve Q or heat then (2) get the energy to melt the copper lastly (3) Subtract both work and the total energy required to completely melt the copper bar is achieved.
