Displacement is d
Vf² = Vi² + 2 g d
(-20²) = (+10²) + 2 (-9.8) d
-19.6 d = 300
d = -15.3 m
negative means lower
time is t
d = Vi t + 1/2 g t²
-15.3 = 10 t + (-4.9) t²
4.9 t² - 10 t -15.3 = 0
t = 3.06 s
Hope this helps -John
Answer:

Explanation:
Gauge pressure at the bottom of the cylinder depends on the height of water in the cylinder
So here we can say that

now when liquid is filled to height "h" in base area "A" then gauge pressure of the liquid at the bottom is given as

now we put the whole liquid into another cylinder with twice radius of the first cylinder
So area becomes 4 times
now by volume conservation we can say that if area is increased by 4 times then height of liquid will decrease by 4 times
so we have

so gauge pressure is given as

Explanation:
d) Magnetic force is the power that pulls materials together (magnet e. g iron)
an example :how magnet can pick up a coin.
e) frictional force produces when two surfaces are in contact with each other.
effects of friction : I) it produces heat
II) it causes loss in power.
Answer:
50km/h
Explanation:
Average velocity = change in distance (or distance travelled) divided by/ the change in time (or time taken.)
The change in distance has been given as 100km.
The change in time is 3pm-1pm = 2 hours.
Therefore the average velocity was 100/2 = 50km/h (to the east).
Hope this helped!
If friction is acting along the plane upwards
then in this case we will have
For equilibrium of 100 kg box on inclined plane we have

also for other side of hanging mass we have

now we have




In other case we can assume that friction will act along the plane downwards
so now in that case we will have

also we have

now we have





<em>So the range of angle will be 23.45 degree to 37 degree</em>