Physics, asked by aila4, 1 year ago

A car moves through 120 Km at a speed of 40 Km/h, and return back at a speed of
60 Km/h. Calculate its average speed.​

Answers

Answered by Anonymous
73

Answer:

Average speed = 48 km/h

Explanation:

Averge \: speed  =   \frac{Total \: distance \: travelled}{Total \: time \: interval}

Total distance travelled = Distance travelled to reach the final point + distance travelled to reach the initial point

According to the question;

Distance travelled to reach the final point = 120 km

Distance travelled to reach the initial point = 120 km

So,

Total distance travelled = 120 km + 120 km = 240 km

Time taken to reach final point =  \frac{Distance \: travelled \:  to \: reach \: the \: final \: point}{Speed \: to \: reach \: the \: final \: point}

In the question it is given that;

Speed to reach the final point = 40 km/h

So,

Time taken to reach final point =  \frac{120 \: km}{40 \: km/h}

Time taken to reach final point = 3 hr

Time taken to reach final point =  \frac{Distance \: travelled \: to \: reach \: the \: initial \: point}{Speed \: to \: reach \: the \: initial \: point}

In the question it is given that;

Speed to reach the initial point = 60 km/hSo,

So,

Time taken to reach final point =  \frac{120 \: km}{60 \: km/h}

Time taken to reach final point = 2 hr

Therefore,

Average \: speed  =  \frac{240 \: km}{3 \: hr + 2 \: hr}  \\  \\  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  =  \frac{240 \: km}{5 \: hr} \\  \\  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  = \: 48 \: km/hr

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