Given :
Vector A has a magnitude of 63 units and points west, while vector B has the same magnitude and points due south.
To Find :
The magnitude and direction of
a) A + B .
b) A - B.
Solution :
Let , direction in north is given by +j and east is given by +i .
So ,
and 
Now , A + B is given by :


Direction of A+B is 45° north of west .
Also , for A-B :


Direction of A-B is 45° south of west .
( When two vector of same magnitude which are perpendicular to each other are added or subtracted the resultant is always 45° from each of them)
Hence , this is the required solution .
Answer:
5.5g of ice melts when a 50g chunk of iron at 80°C is dropped into a cavity
Explanation:
The concept to solve this problem is given by Energy Transferred, the equation is given by,

Where,
Q= Energy transferred
m = mass of water
c = specific heat capacity
Temperature change (K or °C)
Replacing the values where mass is 50g and temperature is 80°C to 0°C we have,



Then we can calculate the heat absorbed by m grams of ice at 0°C, then

How Q_1=Q_2, so



Then 5.5g of ice melts when a 50g chunk of iron at 80°C is dropped into a cavity
Answer:
The magnification is -6.05.
Explanation:
Given that,
Focal length = 34 cm
Distance of the image =2.4 m = 240 cm
We need to calculate the distance of the object

Where, u = distance of the object
v = distance of the image
f = focal length
Put the value into the formula



The magnification is



Hence, The magnification is -6.05.