Answer:
29.4m/s
Explanation:
Given parameters:
Time = 3s
Unknown:
Average velocity = ?
Solution:
To solve this problem, we use the expression below:
v = u + gt
v is the average velocity
u is the initial velocity = 0m/s
g is the acceleration due to gravity = 9.8m/s²
t is the time
So;
v = 0 + (9.8 x 3) = 29.4m/s
Answer:
C) According to the second law of thermodynamics, not all energy from the burnt fuel is used to do work on the piston. It also produces heat which warms other parts of the car.
Explanation:
A) According to the fourth law of thermodynamics, the temperature of the other parts of the car increases due to the coolant used for the engine.
B) According to the first law of thermodynamics, the hood of the car heats up using heat from the surroundings in-order to achieve thermal equilibrium with the engine.
C) According to the second law of thermodynamics, not all energy from the burnt fuel is used to do work on the piston. It also produces heat which warms other parts of the car.
D) According to the third law of thermodynamics, the increase in the velocity of the car changes the entropy of the tires. To balance this change, the temperature of the other parts is increased.
I feel admiration and respect for them, and I feel grateful and humble.
A glacier is frozen and a geyser has boiling water coming from it. A glacier is usually still but it sometimes breaks and a geyser erupts. Also geysers are mostly rare and glaciers aren't.
Answer:
The temperature rise is 
.
Explanation:
Given the mass of the hammer 
is 1.19 kg.
And the speed of the hammer 
is 8.4 m/s.
We need to find the temperature change of iron nail having 20 hammer blows.
First, we will find the kinetic energy of the each blow of hammer.
For 20 such blows, the kinetic energy will be
Let us assume that the nail absorbs all the kinetic energy. So, this 839.8 J will be converted into heat energy 
.
Now,
Also, we know that
Where,
is the mass of the nail, which is 
is the specific heat capacity of iron, which is 449 J/kg.K
is the change in temperature.
Plug these value we get,
We can see the temperature rise is 143.9 K.
