contestada

A golfer rides in a golf cart at an average speed of 3.10 m/s for 21.0 s. she then gets out of the cart and starts walking at an average speed of 1.40 m/s. for how long (in seconds) must she walk if her average speed for the entire trip, riding and walking, is 2.40 m/s?

Respuesta :

osprey2015

A golfer rides in a golf cart at an average speed of 3.10 m/s for 21.0 s.

she then gets out of the cart and starts walking at an average speed of

1.40 m/s. for how long (in seconds) must she walk if her average speed

for the entire trip, riding and walking, is 2.40 m/s?

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avgespeed = total distance/total time

golf cart ...tot dist = 3.1x21.0


walking ...

1.4 = distance/time


combined ...

(3.1x21.0+1.4xt)/(21+t2)=2.4

solve for t2 => 0.7x21