Answer:
scratching a surface to make it rougher
increasing the size of a flying object
adding extra weight to an object
Explanation:
Answer:
1-d
2- a
3-e
4-b
5-c
This is the correct sequence
Waterfalls are created when a river flows following a descending rapid slope. The waterfall, then, flows from the source (where it starts) to the mouth (where it ends).
Waterfalls are created when the erosion of the rocks at the bottom of the slope is more powerful than the erosion of the rocks on the top.
After many years the water is able to erode the rocks on the top as well, and the waterfall slowly disappears.
Therefore the options that apply are:
b) waterfalls move towards their mouth;
c) the top or cap rock is resistant to erosion;
<span>f) waterfalls indicate a youthful river </span>
Answer:30 m
Explanation:
Given
Maximum Horizontal distance is 5 m on earth
launching angle
Acceleration due to gravity on earth is 
Acceleration due to gravity on moon is 
Range of projectile is given by

----1
-----2
Divide 1 & 2


Answer:
P = 1097 Watt
Explanation:
given,
length of stairs, L = 130 m
inclination with horizontal,θ = 30°
mass of the football player = 105 Kg
time = 61 s
we know,

Work = change in Potential energy
h = L sin 30°
h = 130 x 0.5
h = 65 m
W = m g h
W = 105 x 9.8 x 65
W = 66885 J
now,

P = 1097 Watt
hence, the power output on the way is 1097 W