Answer:
option (i) is correct
Explanation:
as there is no air resistance, no force is acting on the object horizontally, but gravitational acceleration will obviously act, regardless of the air resistance... option (i) is correct
When block is pushed upwards along the inclined plane
the net force applied on the block will be given as

here we know that
m = 75 kg


now plug in all values into this


now for finding the power is given as



Answer:
v = 22.54 mph.
Explanation:
Given that,
Distance moved, d = 200 m
Time, t = 19.8 s
We need to find the runner's average speed.
We know that,
1 mile = 1609.34 m
200 m = 0.124 miles
19.8 seconds = 0.0055 h
So,
Speed = distance/time

So, the runner's average speed is 22.54 mph.