Question

1. if a 12.5 kg ball is dropped off a 400m building. how fast is the ball going after 5 seconds?

formulas: __________ fill in formula: __________
answer: ____________

1. if a 15kg ball is dropped off a 140 m building. how far is the ball going to fall in 3 sec?

formula: __________ fill in formula: __________
answer ____________

1. determine the gravitational forces between a 142 g baseball and a 45 g golf ball at a distance of 5 m apart.

formula: ____________
formula fill in: ____________
answer: ____________

1. what is the bf of the foil boat in the diagram below, if the water has a density of 1055 kg/m³

formula : __________ fill __________
answer = ____________

1. the mass of a penny is 2.5 grams and its terminal velocity is 31 m/s². the velocity of a penny traveling at 93 m/s² would kill somebody. if a penny were dropped from a 490m building how fast would it be going, in a vacuum, when it hit the ground?

formula : __________ fill in: __________
answer: ____________

Explanation:

27.

Step1: Identify the formula

The formula for the velocity of a freely - falling object is $v = v_0+gt$, where $v_0 = 0$ (dropped, initial velocity is 0), $g = 9.8m/s^2$ (acceleration due to gravity), and $t$ is the time.
$v=0 + gt$

Step2: Substitute the values

Substitute $g = 9.8m/s^2$ and $t = 5s$ into the formula.
$v=9.8\times5$

Step1: Identify the formula

The formula for the distance fallen by a freely - falling object is $d=v_0t+\frac{1}{2}gt^2$. Since $v_0 = 0$ (dropped), the formula simplifies to $d=\frac{1}{2}gt^2$.
$d=\frac{1}{2}gt^2$

Step2: Substitute the values

Substitute $g = 9.8m/s^2$ and $t = 3s$ into the formula.
$d=\frac{1}{2}\times9.8\times3^2$
$d = 4.9\times9$

Step1: Identify the formula

The formula for the gravitational force between two objects is $F = G\frac{m_1m_2}{r^2}$, where $G=6.67\times 10^{- 11}N\cdot m^2/kg^2$, $m_1$ and $m_2$ are the masses of the two objects, and $r$ is the distance between them. First, convert the masses to kg: $m_1=142g = 0.142kg$, $m_2 = 45g=0.045kg$, and $r = 5m$.
$F = G\frac{m_1m_2}{r^2}$

Step2: Substitute the values

$F=6.67\times 10^{-11}\times\frac{0.142\times0.045}{5^2}$
$F=6.67\times 10^{-11}\times\frac{0.00639}{25}$
$F=6.67\times 10^{-11}\times0.0002556$

Answer:

$49m/s$

28.