What do Rachel's actions reveal about her

Which is not expecting acceleration?

Elena L [17]

#1

A point on the outside of a spinning top whose rotational speed is constant.

Since the point at the top is at rest so it will not accelerate at all

A skydiver whose air resistance is equal to that of her weight.

Since weight is counter balanced by air resistance so net force on it is zero so acceleration will be zero

A car on the freeway experiencing a net force of -120 N.

Since net force is not zero so it will accelerate here

A submerged beach ball whose buoyant force is eight times the force of gravity on it.

Since buoyant force is more than the weight so it will not at rest and move upwards with some acceleration

#2

A frictionless spinning merry go round.

Since spinning wheel accelerating due to centripetal force so it is non inertial frame

A falling rock.

Falling rock is accelerating due to gravity so it is again non inertial frame

A hot air balloon moving at 30 degrees east of north with no net force.

since hot air balloon is having no force on it so its acceleration is zero and its an inertial frame

A space shuttle whose boosters just ignited for takeoff.

Since space shuttle is accelerating due to boosters so it is non inertial frame

#3

Here net force on it is due to two given forces

$F_1 = 4320 N$ towards right

$F_2 = 4380 N$ towards left

so here net force is given as

$F = F_2 - F_1$

$F = 4380 - 4320 = 60 N$

since force towards left is more so the direction will be towards left

so correct answer is 60 N towards left

4 0

3 years ago

What is the name for a wave that requires energy to produce it and a medium to travel through?

Wittaler [7]

....mechanical wave...

8 0

3 years ago

26. The speed of light in a certain medium is

horrorfan [7]

The number we need in order to answer the question belongs in the space between the words "is" and "of". You left that blank blank, so there really isn't any question here to answer.

HOWEVER ... the refractive index of a medium can never be less than 1.0 , so we know for sure that choice-a can't be the correct answer.

6 0

3 years ago

What happens to a chemical reaction when the temperature is increased ?

Andrew [12]

It starts or speeds up.
Some substances need certain amount of energy in order to react with each other.

7 0

3 years ago

Read 2 more answers

A small mailbag is released from a helicopter that is descending steadily at 3 m/s.

mario62 [17]

Answer:

a) Speed of mailbag after 3 seconds = 32.4 m/s

b) Package is 44.1 meter below helicopter

c) If the helicopter was rising steadily at 3.00 m/s

Speed of mailbag after 3 seconds = 26.4 m/s

Package is 44.1 meter below helicopter

Explanation:

a) We have equation of motion, v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration and t is the time taken.

Initial velocity = 3 m/s, acceleration = 9.8 $m/s^2$ and time = 3 seconds.

v = 3+9.8*3 = 32.4 m/s

Speed of mailbag after 3 seconds = 32.4 m/s

b) We have equation of motion , $s= ut+\frac{1}{2} at^2$ , s is the displacement, u is the initial velocity, a is the acceleration and t is the time.

Velocity of helicopter = 3 m/s, time taken = 3 seconds, acceleration = 0 $m/s^2$ .

$s= 3*3+\frac{1}{2} *0*3^2\\ \\ s=9m$

Distance traveled by helicopter = 9 meter.

Velocity of package = 3 m/s, time taken = 3 seconds, acceleration = 9.8 $m/s^2$ .

$s= 3*3+\frac{1}{2} *9.8*3^2\\ \\ s= 53.1m$

Distance traveled by package = 53.1 meter.

So package is (53.1-9)meter below helicopter = 44.1 m

c) Initial velocity = -3 m/s, acceleration = 9.8 $m/s^2$ and time = 3 seconds.

v = -3+9.8*3 = 26.4 m/s

Speed of mailbag after 3 seconds = 26.4 m/s

Velocity of helicopter = -3 m/s, time taken = 3 seconds, acceleration = 0 $m/s^2$ .

$s= -3*3+\frac{1}{2} *0*3^2\\ \\ s=-9m$

Distance traveled by helicopter = 9 meter.

Velocity of package = -3 m/s, time taken = 3 seconds, acceleration = 9.8 $m/s^2$ .

$s= -3*3+\frac{1}{2} *9.8*3^2\\ \\ s= 35.1m$

Distance traveled by package = 35.1 meter.

So package is (35.1+9)meter below helicopter = 44.1 m

4 0

3 years ago