Physics, asked by ankitsingh304293, 1 year ago

the mass of cyclist together with the bike is 90 kg calculate the increasing kinetic energy pte speed increased from 6 km per hour to 12 km per hour

Answers

Answered by smartAbhishek11
4
Total mass of the system (cyclist and bike), M=mc+mb=90 kg

Initial velocity of the system, u=6.0 km/h=1.666 m/sec

Final velocity of the system, ν=12 km/h=3.333 m/sec

From work-energy theorem, we have:
Increase in K.E.=12Mν2−12mu2=1290×(3.333)2−12×90×(1.66)2=499.4−124.6=374.8=375 J
Answered by harisreeps
4

Answer:

The mass of the cyclist together with the bike is 90 kg. The increasing kinetic energy when speed increased from 6 km per hour to 12 km per hour is 375 J.

Explanation:

Given,

The total mass (m)   =  90 kg

Initial speed  \left(V_{i}\right)      =  6 km/hr = 6 \times\frac{5}{18} =\ 1.6666 \ m/s

Final speed  \left(V_{f }\right)      =  12 km/hr =  12 \times\frac{5}{18} =\ 3.3333 \ m/s

We have the expression for Kinetic energy (K.E) as,

\mathrm{K} . \mathrm{E}=\frac{1}{2} m V^{2}

So the change in K.E will be,

\Delta \mathrm{KE}=\frac{1}{2} \mathrm{~m}\left(\mathrm{~V}_{\mathrm{f}}^{2}-\mathrm{V}_{\mathrm{i}}^{2}\right)

          =  \frac{1}{2} \times 90 \times\left(\left\\3.333^{2}-\left\\1.6666^{2}\right)

          =  374.9999 J

          ≈   375 J

Ans:

The Increase in kinetic energy  = 375 J

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