While you are going 60 mph, it will take approximately 180 feet to stop, A is the correct choice. I know some of the question is missing, so I researched it and found the correct answer.
Answer:
it is maybe A but i'm not 100% sure
Explanation:
its the only one that is mixed
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:
![m=\frac{\Delta{U}}{Cv{\Delta{T}}}=\frac{1674}{0.9*[38-(-24)]}=30Kg](https://tex.z-dn.net/?f=m%3D%5Cfrac%7B%5CDelta%7BU%7D%7D%7BCv%7B%5CDelta%7BT%7D%7D%7D%3D%5Cfrac%7B1674%7D%7B0.9%2A%5B38-%28-24%29%5D%7D%3D30Kg)
Answer:
1/√2
Explanation:
Kinetic energy of a body is expressed as
KE = 1/2mv²
If it's KE is doubled
2KE = 1/2mv1² where v1 is the new speed when the kinetic energy is doubled
To know the value of the amount the velocity has changed, we will divide both equations
2KE/KE = (1/2mv²)/(1/2mv1²)
2 = v²/v1²
(v/v1)² = 2
v/v1 = √2
v1 = v/√2
v1 = 1/√2 × v
The new velocity has changed by
1/√2vinitial
<span>When water freezes to form ice, its volume expands. However, we know from conservation of mass that the mass of the ice is the same as the mass of the water. Since density is defined fundamentally as mass / volume, and we have an expanding volume at a constant mass, the denominator of the equation grows, and thus the density of ice is lower than that of liquid water.</span>
