PHYSICS HELP PLS

A tennis player standing 12.6 m from the net hits the ball at 3.18° above the horizontal. To clear the net, the ball must rise a

SOVA2 [1]

At the vertex, it's vertical velocity is 0, since it has stopped moving up and is about to come back down, and its displacement is 0.33m.
So we use v² = u² + 2as (neat trick I discovered just then for typing the squared sign: hold down alt and type 0178 on ur numpad wtih numlock on!!!) ANYWAY.......
We apply v² = u² + 2as in the y direction only. Ignore x direction.
IN Y DIRECTION:
v² = u² + 2as
0 = u² - 2gh
u = √(2gh) (Sub in values at the very end)
So that will be the velocity in the y direction only. But we're given the angle at which the ball is hit (3° to the horizontal). So to find the velocity (sum of the velocity in x and y direction on impact) we can use: sin 3° = opposite/hypotenuse = (velocity in y direction only) / (velocity)
So rearranging,
velocity = (velocity in y direction only) / sin 3°
= √(2gh)/sin 3°
= (√(2 x 9.8 x 0.33)) / sin 3°
= 49 m/s at 3° to the horizontal

3 0

3 years ago

Solar energy can be changed into thermal energy without any work being done. true or false

Black_prince [1.1K]

Answer:

True

Explanation:

3 0

3 years ago

Two rocks weighing 5 Newtons and 10 Newtons are dropped simultaneously from the same height onto a Coyote. After three seconds o

Ilia_Sergeevich [38]

<h2>Potential energy lost by 10 N rock will be greater</h2>

Explanation:

Two rocks of 5N and 10N falls from the same height . Thus they will loose the potential energy.

The potential energy lost = mass x acceleration due to gravity x height

The potential energy lost by first 5 N rock = 5 h

Because weight of rock m g = 5 N

Similarly , the potential energy lost by 10 N Rock = 10 h

here weight of rock m g = 10 N

Thus comparing these two , the potential energy lost by 10 N rock is greater than that of 5 N rock .

5 0

4 years ago

Would the frequency of the angular simple harmonic motion (SHM) of the balance wheel increase or decrease if the dimensions of t

storchak [24]

Answer:

Yes the frequency of the angular simple harmonic motion (SHM) of the balance wheel increases three times if the dimensions of the balance wheel reduced to one-third of original dimensions.

Explanation:

Considering the complete question attached in figure below.

Time period for balance wheel is:

$T=2\pi\sqrt{\frac{I}{K}}$

$I=mR^{2}$

m = mass of balance wheel

R = radius of balance wheel.

Angular frequency is related to Time period as:

$\omega=\frac{2\pi}{T}\\\omega=\sqrt{\frac{K}{I}} \\\omega=\sqrt{\frac{K}{mR^{2}}$

As dimensions of new balance wheel are one-third of their original values

$R_{new}=\frac{R}{3}$

$\omega_{new}=\sqrt{\frac{K}{mR_{new}^{2}}}\\\\\omega_{new}=\sqrt{\frac{K}{m(\frac{R}{3})^{2}}}\\\\\omega_{new}={3}\sqrt{\frac{K}{mR^{2}}}\\\\\omega_{new}={3}\omega$