Answer:D: the velocity is zero
Explanation:
Answer:
The acceleration of a point on the wheel is 11.43 m/s² acting radially inward.
Explanation:
The centripetal acceleration acts on a body when it is performing a circular motion.
Here, a point on the bicycle is performing circular motion as the rotation of the wheel produces a circular motion.
The centripetal acceleration of a point moving with a velocity
and at a distance of
from the axis of rotation is given as:
![a=\frac{v^2}{r}](https://tex.z-dn.net/?f=a%3D%5Cfrac%7Bv%5E2%7D%7Br%7D)
Here, ![v=8\ m/s,r=0.70\ m](https://tex.z-dn.net/?f=v%3D8%5C%20m%2Fs%2Cr%3D0.70%5C%20m)
∴ ![a=\frac{8}{0.70}=11.43\ m/s^2](https://tex.z-dn.net/?f=a%3D%5Cfrac%7B8%7D%7B0.70%7D%3D11.43%5C%20m%2Fs%5E2)
Therefore, the acceleration of a point on the wheel is 11.43 m/s² acting radially inward.
Answer:
The dynamo has a wheel that touches the back tyre. As the bicycle moves, the wheel turns a magnet inside a coil. This induces enough electricity to run the bicycle's lights. The faster the bicycle moves, the greater the induced voltage - and the brighter the lights.
Answer:
Explanation:
Intensity of light is inversely proportional to distance from source
I ∝ 1 /r² where I is intensity and r is distance from source . If I₁ and I₂ be intensity at distance r₁ and r₂ .
I₁ /I₂ = r₂² /r₁²
If r₂ = 4r₁ ( given )
I₁ / I₂ = (4r₁ )² / r₁²
= 16 r₁² / r₁²
I₁ / I₂ = 16
I₂ = I₁ / 16
So intensity will become 16 times less bright .
"16 times " is the answer .