Plzzz helppp I’ll mean a lot it’s for my test 50 points!!<br> Plzzzz helppp

The change of distance concerning to time is defined as speed. Speed is a scalar quantity. It is a time-based component. Its unit is m/sec.

Condition 1;

She takes 25 minutes to run 1,000 m and walk 1,600 m The total time to run as well as the walk is 25 minutes.

$\rm t = t_r +t_w \\\\ 25 = t_r +t_w$

As we know that;

Distance = speed × time

$\rm x_r = v_r \times t_r \\\\ t_r = \frac{x_r}{v_r}$

For walking;

$\rm t_w = \frac{x_w}{v_w}$

$\rm t = t_r +t_w \\\\ 25 = \frac{x_r}{v_r} +\frac{x_w}{v_w} \\\\ 25 = \frac{1000 \ m}{v_r} +\frac{1600 \ }{v_w} \\\\ 40 v_w +64 v_r = v_rv_w$

Same as for condition 2;

$\rm 100 v_w + 40 v_r = v_rv_w$

$\rm 40 v_w +64 v_r =\rm 100 v_w + 40 v_r \\\\ v_r = 2.5 v_w$

Condition 3;

$\rm d_w = 800 \ m$

$\rm d_w = v_w \times t_w$

$\rm t_w = \frac{d_w}{v_w } \\\\ \rm t_w = \frac{800}{v_w } \\\\$

Hence their running speed of Jenny willl be 2.5 times the velocity at she walks.

To learn more about the velocity, refer to the link: brainly.com/question/862972.

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5 0

2 years ago

A 4.0-kg mass is moving with speed 2.0 m/s. A 1.0-kg mass is moving with speed 4.0 m/s. Both objects encounter the same constant

Kazeer [188]

Answer

given,

mass of object 1 = 4 Kg

Speed of object 1 = 2 m/s

mass of object 2 = 1 Kg

speed of object 2 = 4 m/s

KE of the object 1 = $\dfrac{1}{2}MV^2$

= $\dfrac{1}{2}\times 4 \times 2^2$

= 8 J

KE of the object 2 = $\dfrac{1}{2}MV^2$

= $\dfrac{1}{2}\times 1 \times 4^2$

= 8 J

Kinetic energy of both the object is same hence,Work done by both the object will also be same.

It is given that braking force is same in both cases.

So, distance travel by Both the object will be same.

6 0

4 years ago

An 8.0 cm object is 40.0 cm from a concave mirror that has a focal length of 10.0 cm. Its image is 16.0 cm in front of the mirro

svet-max [94.6K]

We can rearrange the mirror equation before plugging our values in.
1/p = 1/f - 1/q.
1/p = 1/10cm - 1/40cm
1/p = 4/40cm - 1/40cm = 3/40cm
40cm=3p <-- cross multiplication
13.33cm = p

Now that we have the value of p, we can plug it into the magnification equation.

M=-16/13.33=1.2
1.2=h'/8cm
9.6=h'

So the height of the image produced by the mirror is 9.6cm.

6 0

3 years ago

Plzzz helppp I’ll mean a lot it’s for my test 50 points!! Plzzzz helppp