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2 years ago

Which phrase describes speed?

Physics

2 answers:

Anna11 [10]2 years ago

6 0

Answer:

the answer is B

Explanation:

speed is the rate at which the distance covered changes or the distance divided by the time taken.

scalar is always positive.

DochEvi [55]2 years ago

6 0

Speed is the distance covered per amount of travel time. Units should be in m/s usually.

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The figure above shows a rod that is fixed to a horizontal surface at pivot P The rod is initially rotating

Lisa [10]

The angular speed is decreasing and direction of rotation clockwise of the rod immediately after time t.

<h3></h3><h3>What is angular speed ?</h3>

The rate of change of angular displacement is defined as angular speed. It is stated as follows:

ω = θ t

Where,

θ is the angle of rotation,

t is the time

ω is the angular velocity

The torque is found as;l

$\rm T = F \times r$

If the force is acting on the rod from the three point is the same, the value of the torque is depends upon the radius or the perpendicular distance.

The perpendicular distance of the right force is grater. Hence, the force acting on the right side is more, and the rod will rotate clockwise.

Both the forces are acting downwards. Thus, the resultant force is the less due to which the speed is increasing.

Hence, the angular speed is decreasing and direction of rotation clockwise of the rod immediately after time t.

To learn more about the angular speed, refer to the link;

brainly.com/question/9684874

#SPJ1

5 0

2 years ago

Sarah, who has a mass of 55 kg, is riding in a car at 20 m/s. She sees a cat crossing the street and slams on the brakes! Her se

avanturin [10]

Answer:

-2200 N

Explanation:

The change in momentum of Sarah is equal to the impulse, which is the product between the force exerted by the seatbelt on Sarah and the time during which the force is applied:

$\Delta p=I\\m \Delta v = F \Delta t$

where

m is the mass

$\Delta v$ is the change in velocity

F is the average force

$\Delta t$ is the duration of the collision

In this problem:, we have:

m = 55 kg is Sarah's mass

$\Delta v = 0-20 = -20 m/s$ is the change in velocity

$\Delta t = 0.5 s$ is the duration of the collision

Solving for F, we find the force exerted by the seatbelt on Sarah:

$F=\frac{m\Delta v}{\Delta t}=\frac{(55)(-20)}{0.5}=-2200 N$

Where the negative sign indicates that the direction of the force is opposite to that of Sarah's initial velocity.

5 0

3 years ago

Which is the largest gas that occurs in our atmosphere?

Mademuasel [1]

Answer:

OXYGEN

Explanation:brainlyist me

6 0

3 years ago

Read 2 more answers

Define force and provide an example

ollegr [7]

Answer:

force-strength,power or energy as an attribute of motion, movement or action. Example: Frictional force.

4 0

3 years ago

A recent home energy bill indicates that a household used 475475 kWh (kilowatt‑hour) of electrical energy and 135135 therms for

faltersainse [42]

Answer:

Explanation:

Given that,.

A house hold power consumption is

475 KWh

Gas used is

135 thermal gas for month

Given that, 1 thermal = 29.3 KWh

Then,

135 thermal = 135 × 29.3 = 3955.5 KWh

So, total power used is

P = 475 + 3955.5

P =4430.5 KWh

Since 1 hr = 3600 seconds

So, the energy consumed for 1hr is

1KW = 1000W

P = energy / time

Energy = Power × time

E = 4430.5 KWhr × 1000W / KW × 3600s / hr

E = 1.595 × 10^10 J

So, using Albert Einstein relativity equation

E = mc²

m = E / c²

c is speed of light = 3 × 10^8 m/s

m = 1.595 × 10^10 / (3 × 10^8)²

m = 1.77 × 10^-7 kg

Then,

1 kg = 10^6 mg

m = 1.77 × 10^-7 kg × 10^6 mg / kg

m = 0.177mg

m ≈ 0.18 mg

5 0

2 years ago