Answer:
2274 J/kg ∙ K
Explanation:
The complete statement of the question is :
A lab assistant drops a 400.0-g piece of metal at 100.0°C into a 100.0-g aluminum cup containing 500.0 g of water at 15 °C. In a few minutes, she measures the final temperature of the system to be 40.0°C. What is the specific heat of the 400.0-g piece of metal, assuming that no significant heat is exchanged with the surroundings? The specific heat of this aluminum is 900.0 J/kg ∙ K and that of water is 4186 J/kg ∙ K.
= mass of metal = 400 g
= specific heat of metal = ?
= initial temperature of metal = 100 °C
= mass of aluminum cup = 100 g
= specific heat of aluminum cup = 900.0 J/kg ∙ K
= initial temperature of aluminum cup = 15 °C
= mass of water = 500 g
= specific heat of water = 4186 J/kg ∙ K
= initial temperature of water = 15 °C
= Final equilibrium temperature = 40 °C
Using conservation of energy
heat lost by metal = heat gained by aluminum cup + heat gained by water

Heaver objects because they have greater mass
Answer: Neighbour
Explanation: Taken perspective from the given clues:
The Neighbor walks to work
The Handyman rides a bike
The Cook rides a motorcycle
The Maid drives a car
The Nephew has a dog
If we assume that the handyman delivered the iPad in the mailbox, then
The direction of the cook, Nephew and his dog are perpendicular to the direction of the bike of the handyman. So, it can't be the cook, Nephew and the maid.
The two suspects are the handyman and the neighbour.
If the handyman actually dropped the iPad and left, then, the neighbour should be the culprit.
Answer:
<h2>
128.61 Watts</h2>
Explanation:
Average power done by the torque is expressed as the ratio of the workdone by the toque to time.
Power = Workdone by torque/time
Workdone by the torque =
= 
I is the rotational inertia = 16kgm²



To get the angular acceleration, we will use the formula;


Workdone by the torque = 16 * 1.28 * 12.56
Workdone by the torque = 257.23 Joules
Average power done by the torque = Workdone by torque/time
= 257.23/2.0
= 128.61 Watts