Ask question

Ask question

All categories

2 years ago

5

A woman hikes 2.5 kilometers in 30 minutes, and then 3 kilometers in 20 minutes, and finally 2 kilometers in 10 minutes. What wa

s her average speed?

1 answer:

nalin [4]2 years ago

3 0

Answer:

7.5 kph

Explanation:

2.5+3+2=7.5

You might be interested in

A point from which the position of other objects can be described is called what?

Alisiya [41]

Answer:

Reference Point

Explanation:

3 0

3 years ago

Spitting cobras can defend themselves by squeezing muscles around their venom glands to squirt venom at an attacker. Suppose a s

Alenkasestr [34]

Answer: 1.289 m

Explanation:

The path the cobra's venom follows since it is spitted until it hits the ground, is described by a parabola. Hence, the equations for parabolic motion (which has two components) can be applied to solve this problem:

<u>x-component: </u>

$x=V_{o}cos\theta t$ (1)

Where:

$x$ is the horizontal distance traveled by the venom

$V_{o}=3.10 m/s$ is the venom's initial speed

$\theta=47\°$ is the angle

$t$ is the time since the venom is spitted until it hits the ground

<u>y-component: </u>

$y=y_{o}+V_{o}sin\theta t+\frac{gt^{2}}{2}$ (2)

Where:

$y_{o}=0.44 m$ is the initial height of the venom

$y=0$ is the final height of the venom (when it finally hits the ground)

$g=-9.8m/s^{2}$ is the acceleration due gravity

Let's begin with (2) to find the time it takes the complete path:

$0=0.44 m+3.10 m/s sin\theta(47\°)+\frac{-9.8m/s^{2} t^{2}}{2}$ (3)

Rewritting (3):

$-4.9 m/s^{2} t^{2} + 2.267 m/s t + 0.44 m=0$ (4)

This is a quadratic equation (also called equation of the second degree) of the form $at^{2}+bt+c=0$ , which can be solved with the following formula:

$t=\frac{-b \pm \sqrt{b^{2}-4ac}}{2a}$ (5)

Where:

$a=-4.9 m/s^{2$

$b=2.267 m/s$

$c=0.44 m$

Substituting the known values:

$t=\frac{-2.267 \pm \sqrt{2.267^{2}-4(-4.9)(0.44)}}{2(-4.9)}$ (6)

Solving (6) we find the positive result is:

$t=0.609 s$ (7)

Substituting (7) in (1):

$x=(3.10 m/s)cos(47\°)(0.609 s)$ (8)

We finally find the horizontal distance traveled by the venom:

$x=1.289 m$

7 0

3 years ago

alukav5142 [94]

Answer:

Gamit ang graphic organizer na concept po punan niyo po ang mga sangay na ito at magpapakita ng paggalang sa kapwa kalaro

3 0

2 years ago

True or false. Students with a Learners License may not receive a motorcycle endorsement.

viktelen [127]

This is a true statement

3 0

3 years ago

ball is dropped from rest and hits the ground 1.1 seconds later. What height was the ball released from?

Aleonysh [2.5K]

Height = 1/2 * 9.8 * (1.1^2)

5 0

3 years ago