Answer: An object is in motion when its distance from another object is changing . A reference point is a place or object used for comparison to determine if something is in motion. An object is in motion if it changes position relative to a reference point. You assume that the reference point is stationary, or not moving

Explanation:

4 0

3 years ago

A linebacker runs at 3 m/s and collides with a running back running towards him at 3.2

Anit [1.1K]

Answer:b

Explanation:

im in fifth grade so i guessd. gl tho heh.

3 0

3 years ago

The opening to a cave is a tall, 30-cm-wide crack. A bat that is preparing to leave the cave emits a 30 kHz ultrasonic chirp. Ho

sweet-ann [11.9K]

Answer:

Width of sound beam is 7.557 m

Explanation:

First we will calculate the wave length from given data:

λ=v/f

Were:

v is the speed

f is the frequency

$\lambda=\frac{340}{30*10^3}\\ \lambda=0.01133 m$

We considered the opening long and narrow, Using single slit diffraction formula:

mλ=dsinΘ

where:

d is the crack width

m is the order

Θ is angle

Considering m=1, The angle between first minimum from center of beam is:

$\theta=sin^{-1}(\frac{m\lambda}{d})\\\theta=sin^{-1}(\frac{1*0.01133}{30*10^{-2}})\\ \theta=2.164^o$

The width of beam is:

tanΘ=y/L

$tan\theta=\frac{w/2}{L}\\ w=2L\ tan\theta\\w=2*100*tan 2.164\\w=7.557 m$

Width=7.557 m

5 0

3 years ago

Which factor listed below has the greatest effect on the period of a pendulum?

Ilya [14]

Answer:

Explanation:

equation for pendulum period is

$\mathrm{T}=2 \pi \sqrt{\frac{\mathrm{L}}{\mathrm{g}}}$

and it depends only on its length (and gravity which is not on the list of answers)

6 0

3 years ago