Ex 1) A Major League baseball pitcher throws a baseball straight up into the air and the ball travels for 4

Assume the space shuttle's main engines produce 764,576 newtons of thrust, and the shuttle has a mass of 78,018 kg. Why does the

Nady [450]

Weight of anything = (mass) x (gravity in the place where the thing is)

Weight of anything on Earth = (mass) x (9.81 m/s²)

Weight of the shuttle = (78,018 kg) x (9.81 m/s²)

Weight of the shuttle, on Earth = 765,357 Newtons

Thrust of main engines = 764,576 Newtons

Are you starting to see the problem yet ?

The weight of the whole thing standing on the launch pad is 751 Newtons more than the maximum thrust of the main engines, and the engines can't lift it ! Even with all throttles wide open, the main engines alone would need about 175 more pounds of thrust to budge that load off the ground. Even with the pedal to the metal, with flame and smoke belching out and covering the whole launch complex, the shuttle would just sit there and never leave the pad.

Well, no. That's not exactly what would happen. As the fuel in the main monster fuel tank is burned, the weight decreases. So it would actually happen like this: After the man announced "Zero ! We have ignition ! All engine running !", the ship would just sit there on the pad ... at first. It would go nowhere and not even wiggle, UNTIL the first 175 pounds of fuel got burned without accomplishing anything. The ship would then be 175 pounds lighter. At that point, the weight would be exactly equal to the thrust of the main engines, and the vertical forces on the ship would be balanced. Then, as MORE fuel continued to be wasted and the weight continued to decrease, the main engines could just begin to lift the ship off the pad.

So the correct answer is choice-D . It tells the whole story, quicker than I can tell it.

4 0

3 years ago

A particular type of automobile storage battery is characterized as "207 - Ampere - hour, 9.4 V."

zepelin [54]

Electric Energy = Current x Voltage x time = 207 x 9.4 = 1,945.8 J

6 0

3 years ago

If she can throw each rock with a speed of 7.5 m/s relative to the ground, causing the wagon to move, how many rocks must she th

Stels [109]

Complete question:

A child sits in a wagon with a pile of 0.64-kg rocks. If she can throw each rock with a speed of 7.5 m/s relative to the ground, causing the wagon to move, how many rocks must she throw per minute to maintain a constant average speed against a 3.9-N force of friction

Answer:

The number of rocks per minutes thrown is 49 rocks/min

Explanation:

Given;

mass of the rock, m = 0.64 kg

speed of the rock, v = 7.5 m/s

frictional force, $f_k$ = 3.9 N

For an object to move at a constant speed, the applied force must be equal to the frictional force.

$f_k = N(F_a)\\\\f_k = N(\frac{mv}{t})\\\\f_k = \frac{N}{t} (mv)\\\\\frac{N}{t} = \frac{f_k}{mv}$

where;

$F_a$ is the applied force

N/t is the number of rocks per minutes thrown

Substitute the given parameters;

$\frac{N}{t} = \frac{f_k}{mv}\\\\ \frac{N}{t} = \frac{3.9}{0.64*7.5}\\\\ \frac{N}{t} = 0.8125 \ \frac{rocks}{second} * \frac{60 \ seconds}{1 \ min} = 48.75 \ \frac{rocks}{min} \$

Approximately 49 rocks/min

5 0

3 years ago

Carmen is helping load furniture and boxes onto a moving truck. She picks up boxes of her things, places them on a cart, and pus

SpyIntel [72]

Answer:

friction is the force she is useing

7 0

3 years ago

Halle la velocidad de las ondas de una cuerda de violin de 820 g/m y 22cm de longitud, si la frecuencia de la fundamental es de

Mice21 [21]

Answer:

your mom B on thezz NUTZ

Explanation:

7 0

3 years ago