An object is 45 m above the ground when it is dropped. How fast is the object going just before it hits the ground?

1 answer:

3 0

This is a kinematics question.
$v^{2} = v_{0} ^{2} + 2g(y - y_{0}) \\ 
v^{2} = 0 + 2(-9.8)(0 - 45) \\ 
v^{2} = 882 \\ v = \sqrt{882} = 29.7 m/s$

You might be interested in

In the flow past a compression corner, the upstream Mach number and pressure are 3.5 and 1 atm, respectively. Downstream of the

yulyashka [42]

Answer:

$\theta=23.7^{\circ}$

Explanation:

The ratio of pressure 2 to 1 us 5.48/1= 5.48 rounded off as 5.5.

Referring to table A.2 of modern compressible flow then $M_{\beta_1}=2.2$

Also

$M_{\beta_1}=M_1 sin \beta$ and making $sin\beta$ the subject of the formula then

$sin\beta=\frac {2.2}{3.5}\\\beta=38.94^{\circ}$

Making reference to $\theta-\beta-M$ diagram then

$\theta=23.7^{\circ}$

4 0

2 years ago

miskamm [114]

B . I hope this is right

4 0

2 years ago

Why do electrons flow threw a wire

Zolol [24]

Answer:

When electric voltage is applied, an electric field within the metal triggers the movement of the electrons, making them shift from one end to another end of the conductor. Electrons will move toward the positive side.

3 0

1 year ago

g When attempting to determine the coefficient of kinetic friction, why is it necessary to move the block with constant velocity

GREYUIT [131]

Answer:

This is because motion is intended to occur but at zero acceleration. It means at a constant velocity, henceFor that to happen the pulling force F must exactly equal the frictional force Fk .

7 0

2 years ago

David lifts a book 1.2 meters from the floor to the top of his desk. If the book weighed 0.50 kg, what is the gravitational pote

Anika [276]

Answer:

5.886 J

Explanation:

Given:

The mass of the book is, $m=0.5$ kg