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)
You should solve this like you would any algebraic expression. Divide both sides by acceleration (a) and you will isolate the mass (m) to one side. Now divide the force (f) by acceleration (a).
F/a=m
Answer: 
Explanation:
Given
Car drives 215 km east and then 45 km North
Displacement is East direction is
Now, the displacement from that to 45 km North is given by
Net displacement is 
Magnitude of the displacement is
Answer:
4.662 slugs
Explanation:
Your mass on the moon should always be the same as any planet you are on (due to law of mass conservation), only your weight be different as gravitational acceleration is different on each planet.
If you weight 150 lbf on Earth, and gravitational acceleration on Earth is 32.174 ft/s2. The your mass on Earth is
m = W / g = 150 / 32.174 = 4.662 slugs
which is also your mass on the moon.
I need this answer too , can someone please help , I have a time limit , please
