Answer:
Explanation:36.05 km
Given
First car travels
South
then turns and travels
east
Suppose south as negative y axis and east as positive x axis
So, ![r_1=-20\hat{j}](https://tex.z-dn.net/?f=r_1%3D-20%5Chat%7Bj%7D)
![r_2=30\hat{i}](https://tex.z-dn.net/?f=r_2%3D30%5Chat%7Bi%7D)
Displacement is the shortest between initial and final point
Dispalcement![=r=r_1+r_2](https://tex.z-dn.net/?f=%3Dr%3Dr_1%2Br_2)
Displacement![=-20\hat{j}+30\hat{i}](https://tex.z-dn.net/?f=%3D-20%5Chat%7Bj%7D%2B30%5Chat%7Bi%7D)
Displacement![=30\hat{i}-20\hat{j}](https://tex.z-dn.net/?f=%3D30%5Chat%7Bi%7D-20%5Chat%7Bj%7D)
Magnitude ![=\sqrt{30^2+(-20)^2}](https://tex.z-dn.net/?f=%3D%5Csqrt%7B30%5E2%2B%28-20%29%5E2%7D)
Magnitude![=36.05\ km](https://tex.z-dn.net/?f=%3D36.05%5C%20km)
Answer:
Explanation:
radius of circle r = 0.9 m.
(a ) In a motion on circular path , work done is zero because force ( centripetal force ) acts perpendicular to displacement .
( b )
Tension in string T = m ω²r
Putting the values
60 = .072 x ω² x 0.9
ω² = 926
ω = 30.4 rad /s
angle made in 20 revolutions θ = 20 x 2π = 126.6 rad
time taken = θ / ω
= 126.6 / 30.4
= 4.16 s .
Answer:
4
Explanation:
In order for the current to continue flowing through the circuit (and for the bulbs to continue shining), there must be a closed path containing the battery where current can flow. Let's see the effect of removing each bulb on the circuit:
- 1: when removing bulb 1 only, the current can still flow through the path battery-bulb 3- bulb 4
- 2: when removing bulb 2 only, the current can still flow through the path battery-bulb 3- bulb 4
- 3: when removing bulb 3 only, the current can still flow through the path battery-bulb 1-bulb 2- bulb 4
- 4: when removing bulb 4 only, the current can no longer flow. In fact, there is no closed path that contains the battery now, so the current will not flow and all the bulbs will stop shining.