Question

Jenny and Alyssa are members of the cross-country team. On a training run, Jenny starts off and runs at a constant 3.8 m/s. Alyssa starts 17 s later and runs at a constant 4.0 m/s.

Answer 1

Answer

given,

speed of jenny = 3.8 m/s

speed of Alyssa = 4 m/s

Alyssa start running after 17 s

we need to calculate time  time after Jenny's start (t i=0 s) does Alyssa catch up with Jenny.

now,

distance traveled by Jenny in 17 s

D = s x t

D = 3.8 x 17 = 64.6 m

now, time taken by Alyssa to cover the distance

speed = 4 - 3.8 = 0.2 m/s

$t = \dfrac{D}{s}$

$t = \dfrac{64.6}{0.2}$

t = 323 s

now, time taken by the Alyssa to caught Jenny after Jenny start running is equal to 323 s.

Answer 2

Answer:

It taken 323 sec by her to covers come jenny.

Explanation:

Given that,

Speed of Jenny = 3.8 m/s

Speed of Alyssa = 4.0 m/s

Suppose ,At what time after Jenny's start does Alyssa catch up with Jenny?

For Jenny,

Distance of Jenny = d

time of Jenny t'= t+17

Speed = 3.8 m/s

For Alyssa,

time = t

distance = d

Speed = 4 m/s

Distance covered by Jenny and Alyssa must be same.

We need to calculate the time

Using formula of distance

$d_{J}=d_{A}$

$4t=3.8(t+17)$

$4t-3.8t-64.6=0$

$t=\dfrac{64.6}{0.2}$

$t=323\ sec$

Hence, It taken 323 sec by her to covers come jenny.