While i believe you forgot to include the ramp options, the least steep and shortest ramp will require the least amount of force. consider this: is it more difficult to push a box up a steep ramp, or a less steep one? a short ramp, or a long ramp?
Answer:
1) The final displacement of cyclist is 20.8 km.
2) The average velocity of cyclist is 18.35 m/h
Explanation:
The path traced by the cyclist is as shown in the attached figure
from the attached figure we can see
1) Initial distance covered = 8.0 km east therefore OA = 8.0 km
2) When the cyclist turns and travels 3.2 km west thus AB = 3.2 km
3) From B the cyclist turns and travels 16 km east thus BC = 16.0 km
As we can see that the total displacement is OC = OA- AB + BC = 8.0-3.2+16 = 20.8 km
Thus the final displacement is 20.8 km.
Part b)
By definition of average velocity we have
Answer
NB:
- speed, U is measure in m/s
- acceleration, a is measured in m/s²
-time t in seconds , s
Therefore conversation must be made
Speed U = 20km/hrs
=20km÷1hr
But 20km= 20×1000=20000m
1hr= 1×60min×60sec=3600s
U=20000÷3600=5.56m/s
a=30km/hrs
=30km÷1hr
But 30km=30×1000=30000
1hr=3600s
a=30000÷3600=8.33m/s²
From the equation of motion
S=Ut + ½ at².
Where s= distance
S = 5.56m/s × 20s + ½(8.33m/s²)(20s)²
S = 1777.3m
Answer:
It takes 11.20 ms for the sphere to increase in potential by 1260 V
Explanation:
Using the formula q = It where I is current in Ampere, and t is in seconds
q = ( 1.000002 - 1.0000000) t
q = 0.000002t
Voltage on the surface of the sphere V = Kq / r
where K is 9.0 × 10⁹ N².m² / c² and
R = 16 cm = 16 /100 = 0.16m
V = Kq /r
substitute the value into q
V = K(0.000002t) / r
cross multiply
rV = K × 0.000002t
make t subject of the formula
t = 0.16 × 1260 / ( 9×10⁹ × 0.000002)
t = 201.6 / ( 18 × 10³)
t = 0.0112 s
= 11.20 ms
It takes 11.20 ms for the sphere to increase in potential by 1260 V
The only statement on the options that says true about density is:
> The density of an object determines whether it will sink or float.
Why?
Density is a physical property of an object.
Density is not derived as a unit of measure. It is derived from 2 fundamental units: kg and m.
The Density of an object is not constant.
Density is calculated by dividing the mass by the volume of an object.