2nd question!!!!!!!!!!!!!!!!!!!

A boy throws a ball vertically up it returns the ground after 10 seconds find the maximum height reached by the ball

Akimi4 [234]

Answer:

Approximately $122.625\; {\rm m}$ (assuming that $g = 9.81\; {\rm m\cdot s^{-2}}$ , the ball was launched from ground level, and that the drag on the ball is negligible.)

Explanation:

Let $v_{0}$ denote the velocity at which the ball was thrown upward.

If the drag (air friction) on the ball is negligible, the ball would land with a velocity of exactly $(-v_{0})$ . The velocity of the ball would be changed from $v$ to $(-v_{0})\!$ (such that $\Delta v = (-v_{0}) - v_{0} = (-2\, v_{0})$ ) within $t = 10\; {\rm s}$ .

Also because the drag on the ball is negligible, the acceleration of the ball would be $a = -g = -9.81\; {\rm m\cdot s^{-2}}$ . Thus:

$\Delta v = a\, t = 10\; {\rm s} \times (-9.81\; {\rm m\cdot s^{-2}}) = -98.1\; {\rm m\cdot s^{-1}}$ .

Since $\Delta v = (-2\, v_{0})$ :

$-2\, v_{0} = \Delta v = -98.1\; {\rm m\cdot s^{-1}$ .

$\begin{aligned}v_{0} &= \frac{-98.1\; {\rm m\cdot s^{-1}}}{-2}= 49.05\; {\rm m \cdot s^{-1}}\end{aligned}$ .

The ball reaches maximum height when its velocity is $v_{1} = 0\; {\rm m\cdot s^{-1}}$ . Apply the SUVAT equation $x = ({v_{1}}^{2} - {v_{0}}^{2}) / (2\, a)$ to find the displacement $x$ between the original position (ground level, where $v_{0} = 49.05\; {\rm m\cdot s^{-1}}$ ) and the max-height position of the ball (where $v_{1} = 0\; {\rm m\cdot s^{-1}}$ .)

$\begin{aligned}x &= \frac{(0\; {\rm m\cdot s^{-1}})^{2} - (49.05\; {\rm m\cdot s^{-1}})^{2}}{2 \times (-9.81\; {\rm m\cdot s^{-2}})} \\ &\approx 122.625\; {\rm m\cdot s^{-1}}\end{aligned}$ .

7 0

1 year ago

an experiment is set up to measure the effect of a gasoline additive on fuel consumption rate. what would be the control in this

Tamiku [17]

The control setup in this experiment would be one tank that does not contain any of the additives. Since the tanks with the gasoline additives would need to be compared with a tank that is not affected by the results of these additives.

4 0

2 years ago

What is the name and symbol of the element in the second row and fourteenth column of the periodic table? Hint: Review your peri

Papessa [141]

The answer is Carbon. Beyond being the only element listed here that is located in the second row, it is also in the fourteenth column of the table if you count from left to right. Hope this helps!

4 0

3 years ago

Scientists are busy in invention of the devices which run from solor energy

timama [110]

Answer:

because solar enegry is a perpetual source of enegry and by using it non renewable sources of enegry can be preserved and also prevents from enegry crisis.

hope its helpful to uh

3 0

3 years ago

In February 2004, scientists at Purdue University used a highly sensitive technique to measure the mass of a vaccinia virus (the

OlgaM077 [116]

Answer:

a) m_v = m_s (( $\frac{w_o}{w}$ )² - 1) , b) m_v = 1.07 10⁻¹⁴ g

Explanation:

a) The angular velocity of a simple harmonic motion is

w² = k / m

where k is the spring constant and m is the mass of the oscillator

let's apply this expression to our case,

silicon only

w₉² = $\frac{K}{m_s}$

k = w₀² m_s

silicon with virus

w² = $\frac{k}{m_s + m_v}$

k = w² (m_v + m_s)

in the two expressions the constant k is the same and q as the one property of the silicon bar, let us equal

w₀² m_s = w² (m_v + m_s)

m_v = ( $\frac{w_o}{w}$ )² m_s - m_s

m_v = m_s (( $\frac{w_o}{w}$ )² - 1)

b) let's calculate

m_v = 2.13 10⁻¹⁶ [( $\frac{20.4}{2.85}$ )² - 1)]

m_v = 1.07 10⁻¹⁴ g

4 0

3 years ago