Ask question

Ask question

All categories

3 years ago

6

Little Timmy wants to measure how tall his house is. He doesn’t have a tape measure but does have a stopwatch. He recruits Big B

ob to climb on his roof and drop a rock. He times the rocks fall and finds it to be 1.67 s. How tall is his house?

1 answer:

Komok [63]3 years ago

6 0

The distance covered by an object accelerating from rest is

D = (1/2) · (acceleration) · (time)² .

In this particular case, 'acceleration' is 9.8 m/s² ... due to gravity.

D = (1/2) · (9.8 m/s²) · (1.67 s)²

D = (4.9 m/s²) · (2.789 s²)

D = 13.67 meters

You might be interested in

Several springs are connected as illustrated below in (a). Knowing the individual springs stiffness k1 = 20 N/m, k2 = 30 N/m, k3

Hatshy [7]

Answer:

The equivalent stiffness of the string is 8.93 N/m.

Explanation:

Given that,

Spring stiffness is

$k_{1}=20\ N/m$

$k_{2}=30\ N/m$

$k_{3}=15\ N/m$

$k_{4}=20\ N/m$

$k_{5}=35\ N/m$

According to figure,

$k_{2}$ and $k_{3}$ is in series

We need to calculate the equivalent

Using formula for series

$\dfrac{1}{k}=\dfrac{1}{k_{2}}+\dfrac{1}{k_{3}}$

$k=\dfrac{k_{2}k_{3}}{k_{2}+k_{3}}$

Put the value into the formula

$k=\dfrac{30\times15}{30+15}$

$k=10\ N/m$

k and $k_{4}$ is in parallel

We need to calculate the k'

Using formula for parallel

$k'=k+k_{4}$

Put the value into the formula

$k'=10+20$

$k'=30\ N/m$

$k_{1}$ ,k' and $k_{5}$ is in series

We need to calculate the equivalent stiffness of the spring

Using formula for series

$k_{eq}=\dfrac{1}{k_{1}}+\dfrac{1}{k'}+\dfrac{1}{k_{5}}$

Put the value into the formula

$k_{eq}=\dfrac{1}{20}+\dfrac{1}{30}+\dfrac{1}{35}$

$k_{eq}=8.93\ N/m$

Hence, The equivalent stiffness of the string is 8.93 N/m.

3 0

3 years ago

Sound is repeated near hills.why

Anon25 [30]

Answer:

Sound waves are reflected back

5 0

2 years ago

An object traveling at 1.5 rad

Veronika [31]

The object's final velocity, given the data is 10.5 rad/s

<h3>What is acceleration? </h3>

This is defined as the rate of change of velocity which time. It is expressed as

a = (v – u) / t

Where

a is the acceleration
v is the final velocity
u is the initial velocity
t is the time

<h3>How to determine the final velocity</h3>

The following data were obtained from the question

Initial velocity (u) = 1.5 rad/s
Acceleration (a) = 0.75 rad/s²
Time (t) = 12 s
Final velocity (v) = ?

The final velocity can be obtained as follow:

a = (v – u) / t

0.75 = (v – 1.5) / 12

Cross multiply

v – 1.5 = 0.75 × 12

v – 1.5 = 9

Collect like terms

v = 9 + 1.5

v = 10.5 rad/s

Thus, the final velocity of the object is 10.5 rad/s

Learn more about acceleration:

brainly.com/question/491732

#SPJ1

6 0

1 year ago

What is the advantage of having different shaped beaks? Question 4 options: To protect itself against prey. To be able to eat th

Pavlova-9 [17]

Answer:

To be able to eat the food readily available in the environment

3 0

2 years ago

A Sonometer wire of length

Scrat [10]

Answer:

-75 cm

Explanation:

At l ; F = 350 Hz

At l + 15 cm ; F = 280 Hz

I = 350

I + 15 = 280

280I = 350(I + 15)

280I = 350I + 5250

280I - 350I = 5250

-70I = 5250

I = - 75cm

The length is - 75 cm

4 0

2 years ago