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3 years ago

A satellite is held in orbit by a 2000- N gravitational

Physics

1 answer:

KengaRu [80]3 years ago

4 0

Answer:

The work done by gravity is zero.

Explanation:

Given that,

Gravitational force = 2000 N

Circumference = 80000 km

We need to calculate the work done by gravity

Using formula of work done

$W=F\cdot d\cos\theta$

Here, $\cos\theta$ = 0

Because, for a circular motion is always perpendicular to the force.

Where, F = force

d = distance

Put the value into the formula

$W=2000\times80000\times0$

$W=0$

Hence, The work done by gravity is zero.

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A certain fuel-efficient hybrid car gets gasoline mileage of 55.0 mpg (miles per gallon). (a) If you are driving this car in Eur

ololo11 [35]

We will start by defining the units and their respective equivalences between the proposed measurement systems

$1km = 0.6214mi$

$1gallon = 3.788 litres$

PART A ) The mileage of the car is 55mpg (Miles per gallon)

$55mpg = 55(\frac{miles}{gallon}) (\frac{1km}{0.6214miles})(\frac{1gallon}{3.788L})$

$55mpg = 23.4km/L$

Therefore the mileage of the car is 23.4km/L

PART B ) The mileage of the car means that the car travels 23.4km and consumes 1 liter of fuel. Then

$1L = 23.4km$

For the car to travel 1500km the amount of fuel would be,

$1500km= (1500km)(\frac{1L}{23.4km})$

$1500km = 64.1L$

But 1 gas tank can only hold 45Liters of fuel, then the number of tank required would be

$\text{Number of tanks required} = \frac{64.1L}{45L}$

$\text{Number of tanks required} = 1.4tanks$

Thus the number of tanks of gas required to drive 1500km is 1.4

6 0

3 years ago

When an object is dropped from the top of a tall cliff, your teacher tells you to use -10 m/s2 for the approximate acceleration

Romashka-Z-Leto [24]

1. Answer: Option C

Displacement is a vector quantity. It has both magnitude as well as direction. Hence, it can be positive, zero or negative. In the given question, downward direction is taken as negative. This we have come to know from the downward acceleration $-10m/s^2$ . The negative sign indicates that downward direction is considered negative.

Now, since the object is dropped from the top. The displacement should be negative, because the negative represent a downward direction.

2. Answer: velocity

The truck is travelling at 30 mph to the west. From the unit mph (miles per hour), we know its a magnitude of velocity. West indicates the direction. Hence, the given quantity is a vector -velocity.

It is not speed because speed only indicates the magnitude and not the direction. speed is a scalar quantity.

3 0

2 years ago

Read 2 more answers

Skater 1 has a mass of 45 kg and is at rest. Skater 2 has a mass of 50 kg and is moving slowly at a constant velocity of 3.2 m/s

algol13

Answer:

None

Explanation:

Force, F is given by ma where m is the mass of an object and a is acceleration

Acceleration is the rate of change in velocity per unit time. Since skaters with mass of 75 kg and 50 kg are moving at a constant speed, there is no acceleration hence F=50*0=0 and F=75*0=0

For skater of 45 kg, he is at rest to mean the initial and final velocitu of the skater is zero hence no acceleration, the force will be 45*0=0

Therefore, none of the skaters will experience a greater net force.

3 0

3 years ago

WILL MARK BRAINLIST!!! only for correct answer<br> NEED CORRECT ANSWER ASAPPP

Nataly [62]

Answer:

number 4

Explanation:

The reflection of light happens when the light bounces off the reflecting surface. That is described by the last (bottom) schematics.

Therefore, select answer number 4.

5 0

2 years ago

The brightest star in the night sky in the northern hemisphere is Sirius. Its distance from Earth is estimated to be 8.7 light y

katen-ka-za [31]

Answer: $5.11(10)^{13}miles$

Explanation:

A light year is a unit of length and is defined as "the distance a photon would travel in vacuum during a Julian year at the speed of light at an infinite distance from any gravitational field or magnetic field. "

In other words: It is the distance that the light travels in a year.

This unit is equivalent to $5.879(10)^{12}miles$ , which mathematically is expressed as:

$1Ly=5.879(10)^{12}miles$

Doing the conversion:

$8,7Ly.\frac{5.879(10)^{12}miles}{1Ly}=5.11(10)^{13}miles$ This is the distance from Earth to Sirius in miles.

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2 years ago