Answer:
The mass of the Al-duckie should be 30 kg.
Explanation:
We will use the first law of thermodynamics:
ΔU = m·Cv·ΔT
Since the specific heat of water is 4.185 J(gºC), the change in the water's internal energy would be:
ΔU = 100 kg · 4.185 J(gºC) · (42ºC - 38ºC) = 1674 KJ
Given that no heat is lost, all the internal energy that the water loses while cooling down will transfer to the duckie. So, if the duckie has ΔU = 1674 KJ and its final temperature is the desired 38 ºC, we can calculate its mass using the first law again:
Answer: The velocity of the ball the ball after collision is 5.5 m/s.
Explanation:
John hitting the bottle which is at rest means this is an Elastic collision.
Mass of the ball=
Velocity of ball before collision =
Velocity of ball after collision =
Mass of the bottle=
Velocity of bottle before collision = (bottle is at at rest)
Velocity of bottle after collision =
The velocity of the ball the ball after collision is 5.5 m/s.
Answer:
The accerlation is a derived from the other quantities like change in velocity/time take etc.
Answer: Form a hypothesis
A scientific way to investigate a problem involves mainly five steps.
→A question or problem must be formulated in the first step.
→After gathering the background information, A hypothesis must be made.
→Third step would be to design an experiment.
→Fourth step would include collection and recording of data.
→Fifth step would include the conclusions drawn from the experiment and communication of hypothesis and its results.
When the scientist notices that a dark colored peppered moth over light colored background, he formulates a question: whether the difference in visibility affects the survival rate of dark moths or not? Therefore, next step in the scientific method would be to gather more information on the subject and formulate a hypothesis.
Answer:
Explanation:
b. left block.
c. justified block.
d. modified block.