knowledge of first aid ... eg St John Ambulance, Red Cross etc. I think that everyone in a school should be taught First Aid.
Answer:
In coin card experiment smooth card is used so that the card can slide easily from glass
Answer:
The answer is C
Explanation:
Force is a vector quantity so it has both magnitude and direction. The question shows 20N act as magnitude and Southeast act as direction.
Answer:
Q = - 256 X 10⁻⁷ C .
Explanation:
Electric field due to a charge Q at a distance d from the center is given by the expression
E = k Q /d² Where k is a constant and it is equal to 9 x 10⁹
Put the given value in the equation
9 x 10² = 
Q = 
Q = - 256 X 10⁻⁷ C .
It will be negative in nature as the field is directed towards the center.
Answer: Final temperature is 34.15°C.
Explanation: When two objects have different temperature, they will exchange heat energy until there is no more net energy transfer between them. At that state, the objects are in <u>thermal</u> <u>equilibrium</u>.
So, when in equilibrium, the total heat flow must be zero, i.e.:

In our case, there will be a change in state of ice into water, so total heat flow will be:

where
m₁ is mass of ice
m₂ is mass of water
c₁ is specific heat of ice
c₂ is specific heat of water
is final temperature
is initial temperature
L is latent heat fusion
Temperature is in Kelvin so the transformation from Celsius to Kelvin:
For ice:
T = -15 + 273 = 258K
For water:
T = 48 + 273 = 321K
Solving:



307.15K
In Celsius:
34.15°C
Final temperature of the system when in equilibrium is 34.15°C