Currently, the magnetic south pole lies about ten degrees distant from the geographic north pole, and sits in the Arctic Ocean north of Alaska. The north end on a compass therefore currently points roughly towards Alaska and not exactly towards geographic north.
Answer:
Explanation:
Let the velocity of projectile be v and angle of throw be θ.
The projectile takes 5 s to touch the ground during which period it falls vertically by 100 m
considering its vertical displacement
h = - ut +1/2 g t²
100 = - vsinθ x 5 + .5 x 9.8 x 5²
5vsinθ = 222.5
vsinθ = 44.5
It covers 160 horizontally in 5 s
vcosθ x 5 = 160
v cosθ = 32
squaring and adding
v²sin²θ +v² cos²θ = 44.4² + 32²
v² = 1971.36 + 1024
v = 54.73 m /s
Explanation:
because it doesn't depend upon other unit like kg meter and second
By law of refraction we know that image position and object positions are related to each other by following relation

here we know that



now by above formula


so apparent depth of the bottom is seen by the observer as h = 3.39 cm
There are different options here but all of them work by approximating and assuming.
i) that the boulder is above ground.
ii) that the bottom surface of the boulder is known.
iii) the shape of the boulder is taken into account.
The most accurate way is measuring it by displacement method but the boulder is immovable hence the volume can be calculated by measuring the boulder or a waterproof box to be built around the boulder and calculate the volume occupied by boulder.
All the above methods are estimating methods.
*Another way to find the density is through specific gravity.
S.G = <u>Density</u><u> </u><u>of</u><u> </u><u>object</u>
Density of water
If the material that makes the boulder is known that is if it's stone or a mineral then the specific gravity can be found.
If the boulder is purely rock then S.G lies between 3 - 3.5 and the density of water is known thus the density of the boulder can be found without moving the boulder.
This is what I think after correction and allthe best!