Answer:
time taken with speed 23 km/h will be 1.8 hours or 1 hour 48 minutes
Explanation:
Given:
Time is inversely proportional to the speed
mathematically,
t ∝ (1/r)
let the proportionality constant be 'k'
thus,
t = k/r
therefore, for case 1
time = 3 hr
speed = 14 km/hr
3 = k/14
also,
for case 2
let the time be = t
r = 23 km/h
thus,
we have
t = k/23
on dividing equation 2 by 1
we get
![\frac{t}{3}=\frac{k/23}{k/14}](https://tex.z-dn.net/?f=%5Cfrac%7Bt%7D%7B3%7D%3D%5Cfrac%7Bk%2F23%7D%7Bk%2F14%7D)
or
![t=\frac{14\times3}{23}](https://tex.z-dn.net/?f=t%3D%5Cfrac%7B14%5Ctimes3%7D%7B23%7D)
or
t = 1.8 hr = or 1 hour 48 minutes ( 0.8 hours × 60 minutes/hour = 48 minutes)
Answer:
yes you are totally right
Answer:
(a) 3.24 w (b) 44.44 ohm
Explanation:
It is given that car draws 0.27 A current so current I = 0.27 A
The system has a voltage of 12 V
(a) Electrical power = voltage ×current ![=12\times 0.27=3.24W](https://tex.z-dn.net/?f=%3D12%5Ctimes%200.27%3D3.24W)
(b) The resistance is defined as the ratio of voltage and current
So resistance ![R=\frac{V}{I}=\frac{12}{0.27}=44.44 ohm](https://tex.z-dn.net/?f=R%3D%5Cfrac%7BV%7D%7BI%7D%3D%5Cfrac%7B12%7D%7B0.27%7D%3D44.44%20ohm)
Answer:
300 m/s
Explanation:
The difference in time between the two bangs is 1 s.
Thus;
t2 - t1 = 1
We know that distance/time = speed.
Thus;
d2/v - d1/v = 1
Multiply through by v to get;
d2 - d1 = v
Where v is speed of sound in air.
d1 = 350 m
d2 = (150 × 2) + 350 = 650 m
Thus;
v = d2 - d1 = 650 - 350 = 300 m/s