Answer:
a) 17.086m
b) 0.1671 m
Explanation:
Given data: speed of water through the hose = 1.81 m/s
through the nozzle = 18.3 m/s
We know that maximum height of an object with upward velocity v is given by,
a) H = v^2/2g
where H is the maximum height water emerges
= 18.3^2/(2×9.8) = 17.086 m answer
b) Again,
H = v^2/2g
= 1.81^2/(2×9.8) = 0.1671 m
Well first of all, I think the students may have been correct.
If they didn't use distilled water, and if it wasn't exactly at
standard temperature, then the mass of 25.0 mL could
very well be 25.4 grams. We don't know that there was
any 'error' in their measurement at all.
But the question says there was, so we'll do the math:
The 'error' was (25.4 - 25.0) = +0.4 gram
As a fraction of the 'real' value, the error was
+0.4 / 25.0 = +0.016 .
To change a decimal to a percent, move the
decimal point two places that way ===> .
+ 0.016 = +1.6 % .
Their measurement was 1.6% too high.
Let's not call it an 'error'. Let's just call it a 'discrepancy'
between the measured value and the 'accepted' value. OK ?
Change minutes to hrs, divide by 60:
30 min = .50 hrs
45 min = .75 hrs
12 min = .20 hrs
----------------
total + 1.45 hrs, total travel time
:
let a = average speed for the trip
:
Write a dist equation, dist = speed * time
:
80(.5) + 100(.20) + 40(.75) = 1.45a
40 + 20 + 30 = 1.45a
90 = 1.45a
a =
a = 62.069 km/h, for the entire trip
and
90 km is the total distance
Answer:
Fnet = 0
Explanation:
- Since the block slides across the floor at constant speed, this means that it's not accelerated.
- According Newton's 2nd Law, if the acceleration is zero, the net force on the sliding mass must be zero.
- This means that there must be a friction force opposing to the horizontal component of the applied force, equal in magnitude to it:
- In the vertical direction, the block is not accelerated either, so the sum of the normal force and the vertical component of the applied force, must be equal in magnitude to the force of gravity on the block:
⇒ 169 N + Fn = Fg = 216 N (3)
- This means that there must be a normal force equal to the difference between Fappy and Fg, as follows:
- Fn = 216 N - 169 N = 47 N (4)
