They have a north and South Pole .The opposite poles attract to each other ,the same poles repel from each other.
Answer:
a) 
b) This value of specific heat is close to the specific heat of ice at -40° C and the specific heat of peat (a variety of coal).
c) The material is peat, possibly.
d) The material cannot be ice because ice doesn't exists at a temperature of 100°C.
Explanation:
Given:
- mass of aluminium,

- mass of water,

- initial temperature of the system,

- mass of copper block,

- temperature of copper block,

- mass of the other block,

- temperature of the other block,

- final equilibrium temperature,

We have,
specific heat of aluminium, 
specific heat of copper, 
specific heat of water, 
Using the heat energy conservation equation.
The heat absorbed by the system of the calorie-meter to reach the final temperature.



The heat released by the blocks when dipped into water:

where
specific heat of the unknown material
For the conservation of energy : 
so,


b)
This value of specific heat is close to the specific heat of ice at -40° C and the specific heat of peat (a variety of coal).
c)
The material is peat, possibly.
d)
The material cannot be ice because ice doesn't exists at a temperature of 100°C.
Answer:
Smallest drop: Water
Largest drop: Dirt
Explanation:
The heat needed to change the temperature of a sample is:
(1)
with Q the heat (added(+) or removed(-)), c specific heat, m the mass and
the change in temperature of the sample. So, if we solve (1) for
Sample A:


Sample B:


Sample C:


Note that the numbers 16744, 5400, 9450 are in the denominator of the expression
that gives the drop on temperature. so, if Q is the same for the three samples the smallest denominator gives the largest drop and vice versa.
So, the smallest drop is Sample A and the largest is Sample C.
(Important: The minus sign of
implies the temperature is dropping)
Explanation:
w = f x d
45 x 1.4 = 630j
to get newton's do 45 x gravitation field strength
Answer:
A
Explanation:
Straight line with a negative slope
On a velocity_time graph