Answer:
Total energy is constant
Explanation:
The laws of thermodynamics state that thermal energy (heat) is always transferred from a hot body (higher temperature) to a cold body (lower temperature).
This is because in a hot body, the molecules on average have more kinetic energy (they move faster), so by colliding with the molecules of the cold body, they transfer part of their energy to them. So, the temperature of the hot body decreases, while the temperature of the cold body increases.
This process ends when the two bodies reach the same temperature: we talk about thermal equilibrium.
In this problem therefore, this means that the thermal energy is transferred from the hot water to the cold water.
However, the law of conservation of energy states that the total energy of an isolated system is constant: therefore here, if we consider the hot water + cold water as an isolated system (no exchange of energy with the surroundings), this means that their total energy remains constant.
The recoil velocity of cannon is (4) 5.0 m/s
Explanation:
We can find the recoil velocity from the law of conservation of momentum.
The recoil velocity is velocity of body 2 after release of body 1, i.e. velocity of cannon after release of clown.
Let v2 be cannon's velocity, v1 be clown's velocity given = 15 m/sec
m1 be clown's mass = 100kg and m2 be cannon's mass given = 500kg.
So recoil velocity of cannon v2 is given by,
v2 = -(m1÷m2)v1
v2 = -(100÷500)15
v2 = -5 m/s
where the minus sign refers to the direction of cannon's recoil velocity being opposite to that of clown.
Hence, option (4)5.0 m/s is the correct answer.
Answer:
The white car will cover the most distance every second.
Explanation:
The formula for the uniform speed of an object is given as follows:

where,
s = distance covered by the object
v = speed of the object
t = time required
Now, if we assume time to be constant at 1 s. Then the distance covered by each car will be directly proportional to the speed of the car. Hence, the car with the greatest speed will travel the greatest distance in 1 second.
We, have:
Speed of white car > Speed of red car > Speed of green car
<u>Therefore, the white car will cover the most distance every second.</u>
Answer:
is this a physics questions???
and i didnt get u btw