1-5 answer please .....

A small ball is attached to the lower end of a 0.800-m-long string, and the other end of the string is tied to a horizontal rod.

mestny [16]

Answer:

a = 17.68 m/s²

Explanation:

given,

length of the string, L = 0.8 m

angle made with vertical, θ = 61°

time to complete 1 rev, t = 1.25 s

radial acceleration = ?

first we have to calculate the radius of the circle

R = L sin θ

R = 0.8 x sin 61°

R = 0.7 m

now, calculating at the angular velocity

$\omega =\dfrac{2\pi}{T}$

$\omega =\dfrac{2\pi}{1.25}$

ω = 5.026 rad/s

now, radial acceleration

a = r ω²

a = 0.7 x 5.026²

a = 17.68 m/s²

hence, the radial acceleration of the ball is equal to 17.68 rad/s²

7 0

3 years ago

Suppose a wheel with a tire mounted on it is rotating at the constant rate of 2.59 times a second. A tack is stuck in the tire a

Vesna [10]

Answer:

Tangential speed=5.4 m/s

Radial acceleration= $88.6m/s^2$

Explanation:

We are given that

Angular speed=2.59 rev/s

We know that

1 revolution= $2\pi rad$

2.59 rev= $2\pi\times 2.59=5.18\pi=5.18\times 3.14=16.27 rad/s$

By using $\pi=3.14$

Angular velocity= $\omega=16.27rad/s$

Distance from axis=r=0.329 m

Tangential speed= $r\omega=16.27\times 0.329=5.4m/s$

Radial acceleration= $\frac{v^2}{r}$

Radial acceleration= $\frac{(5.4)^2}{0.329}=88.6m/s^2$

6 0

3 years ago

If your speed changes from 10 km/h to 6 km/h, you have a(n) ______ acceleration.

Delicious77 [7]

If your speed changes from 10 km/h to 6 km/h then
you have an acceleration.

Whether it's a positive or negative one completely depends
on which direction you decided to call the positive direction,
when you started considering your speed and its changes.

If you decided to call the direction in which you're traveling
the positive direction, then a decrease in your speed is a
negative acceleration.

But you could just as easily have said that you're traveling
in the negative direction. If you did that, then a decrease in
your speed would be a positive acceleration.

It's completely up to you, and how you define things.

8 0

3 years ago

Read 2 more answers

A student throws a rock upwards. The rock reaches a maximum height 2.4 seconds after it was released.

Allisa [31]

Answer:

23.52 m/s

Explanation:

The following data were obtained from the question:

Time taken (t) to reach the maximum height = 2.4 s

Acceleration due to gravity (g) = 9.8 m/s²

Initial velocity (u) =..?

At the maximum height, the final velocity (v) is zero. Thus, we can obtain how fast the rock (i.e initial velocity)

was thrown as follow:

v = u – gt (since the rock is going against gravity)

0 = u – (9.8 × 2.4)

0 = u – 23.52

Collect like terms

0 + 23.52 = u

u = 23.52 m/s

Therefore, the rock was thrown at a velocity of 23.52 m/s.

7 0

3 years ago

If the half-life of tritium (hydrogen-3) is 12.3 years, how much of

tatyana61 [14]

Answer:

0.0000076 grams

Explanation:

We're given the half life of Tritium to be 12.3 years. In order to find out the amount of substabce remaining:

Let's first find how many 'half lives' are in 250 years.

$n = \frac{250}{12.3} = 20.325$

Now what is half life? It means the time taken for a given quantity of an element to lose half it's mass.

So in 12.3 years we can find that The amount of 250 g of Tritium will be 250/2 = 125 g. In 24.6 years we'll have 125/2 = 62.5 g

So now we can devise a formula:

$m = \frac{original \: amount}{ {2}^{n} }$

Where m is the remaining amount and n is th number of half lives in the time given.

Using this formula we can calculate:

$m = \frac{10}{ {2}^{20.325} }$

Doing this calculation we get:

$m = 0.0000076 \: g$

As we can see a very small value remains.

4 0

3 years ago