Stars set about how many minutes earlier each day?<br><br> A. 8<br> B. 6<br> C. 4<br> D. 2

A football player kicks a ball at a 30o angle from the ground with an initial velocity of 15 m/s. What is the final velocity of

navik [9.2K]

Given that,

Angle = 30°

Initial velocity = 15 m/s

We need to calculate the time of flight

Using formula of time of flight

$T=\dfrac{2u\sin\theta}{g}$

Where, u = initial velocity

g = acceleration due to gravity

Put the value into the formula

$T=\dfrac{2\times15\sin30}{9.8}$

$T=1.5\ sec$

We need to calculate the final velocity of the ball

Using equation of motion

$v=u+gt$

$v=15+9.8\times1.5$

$v=29.7\ m/s$

Hence, The final velocity of the ball is 29.7 m/s.

7 0

3 years ago

A tennis ball with mass m travelling west,hits a wall with a velocity of v.It bounces back with a velocity 1 ,63 v an easterly d

Pepsi [2]

Answer:

163 v an easterly direction

6 0

3 years ago

If a scientist gets unexpected results during the first trial of an experiment,

My name is Ann [436]

Answer:

A. Repeat the experiment to be sure the results are valid.

5 0

1 year ago

Read 2 more answers

A 95 kg fullback, running at 8.2 m/s, collides in midair with a 128 kg defensive tackle moving in the opposite direction. Both p

Sindrei [870]

Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions here.

Below is the answers:

Fullback running

<span>Mo = mass * velocity </span>
<span>Mo = 95kg * 8.2 m/s =779 kg*m/s (a </span>

<span>He got stopped Change in Mo = 779 kg*m/s (b </span>

<span>Both stopped ===> Tackle's mo = - Halfback's Mo = - 779 kg*m/s (c & d </span>

<span>- 779 = 128 * v </span>
<span>v= - 6.09 m/s (e</span>

6 0

3 years ago

A person is standing on an elevator initially at rest at the first floor of a high building. The elevator then begins to ascend

GREYUIT [131]

Answer:

The found acceleration in terms of h and t is:

$a=\frac{h}{5(t_1)^2}$

Explanation:

(The complete question is given in the attached picture. We need to find the acceleration in terms of h and t in this question)

We are given 3 stages of movement of elevator. We'll first model them each of the stage one by one to find the height covered in each stage. After that we'll find the total height covered by adding heights covered in each stage, and equate it to Total height h. From that we can find the formula for acceleration.

<h3></h3><h3>Stage 1</h3>

Constant acceleration, starts from rest.

Distance = $y = \frac{1}{2}a(t_1)^2$

Velocity = $v_1=at_1$

<h3>Stage 2</h3>

Constant velocity where

Velocity = $v_o=v_1=at_1$

Distance =

<h3> $y_2=v_2(t_2)\\\text{Where~}t_2=4t_1 ~\text{and}~ v_2=v_1=at_1\\y_2=(at_1)(4t_1)\\y_2=4a(t_1)^2\\$ </h3><h3 /><h3>Stage 3</h3>

Constant deceleration where

Velocity = $v_0=v_1=at_1$

Distance =

$y_3=v_1t_3-\frac{1}{2}a(t_3)^2\\\text{Where}~t_3=t_1\\y_3=v_1t_1-\frac{1}{2}a(t_1)^2\\\text{Where}~ v_1t_1=a(t_1)^2\\y_3=a(t_1)^2-\frac{1}{2}a(t_1)^2\\\text{Subtracting both terms:}\\y_3=\frac{1}{2}a(t_1)^2$

<h3>Total Height</h3>

Total height = y₁ + y₂ + y₃

Total height = $\frac{1}{2}a(t_1)^2+4a(t_1)^2+\frac{1}{2}a(t_1)^2 = 5a(t_1)^2$

<h3 /><h3>Acceleration</h3>

Find acceleration by rearranging the found equation of total height.

Total Height = h

h = 5a(t₁)²

$a=\frac{h}{5(t_1)^2}$

6 0

3 years ago

Stars set about how many minutes earlier each day? A. 8 B. 6 C. 4 D. 2