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Murljashka [212]

2 years ago

14

Which of the following quantities are vectors?

1 answer:

Arte-miy333 [17]2 years ago

3 0

Answer:

electric fields

Explanation:

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A boy throws a ball of mass 0.22 kg straight upward with an initial speed of 29 m/s. When the ball returns to the boy, its speed

maksim [4K]

Answer:

The work is -67.76 J

Explanation:

The law of conservation of energy is considered one of one of the fundamental laws of physics and states that the total energy of an isolated system remains constant. except when it is transformed into other types of energy.

This is summed up in the principle that energy can neither be created nor destroyed in the universe, only transformed into other forms of energy.

In this case you must calculate the loss of kinetic energy. This loss is actually the work done against the resistive force in the air. Friction is the only force other than gravity that acts on the ball.

So, the loss of kinetic energy is $\frac{1}{2} *m*(vf^{2} -vi^{2} )$

You know:

mass=m=0.22 kg
Initial velocity of the ball: $vi= 29 \frac{m}{s}$

Final velocity of the ball: $vf= 15 \frac{m}{s}$

Replacing:

$\frac{1}{2} *0.22 kg*(15^{2} -29^{2} )$ = -67.76 J

Friction work is always negative because friction is always against displacement.

<u><em>The work is -67.76 J</em></u>

5 0

3 years ago

URGENT!!! DUE AT 11:59, PLEASE DON’T POST A LINK FOR THIS ANSWER AND BE STRAIGHT FORWARD! Bronco the skydiver, whose mass is 100

kirill [66]

a = 7.8 m/s^2

Explanation:

Let Fnet = net force = ma

m = mass of the skydiver

a = acceleration caused by Fnet

W = weight = mg

f(air) = frictional force due to air resistance

Fnet = W - f(air)

= (100 kg)(9.8 m/s^2) - (200 N)

= 780 N

Therefore, the acceleration of the skydiver due to Fnet is

a = Fnet/m

= (780 N)/(100 kg)

= 7.8 m/s^2

4 0

2 years ago

Joffrey talks and moves slowly. When asked a question, he answers slowly in monotone monosyllables, if he answers at all. Joffre

lana [24]

Answer:

R.E.T.A.R.D.A.T.I.O.N

Explanation:

It won't let me spell it normal

7 0

3 years ago

Suppose a moving car has 2000 J of kinetic energy. If the carʹs speed doubles, how much kinetic energy would it then have?

Bond [772]

Answer:

option A

Explanation:

given,

Kinetic energy of the car = 2000 J

speed of the car is doubled

we know,

$KE_1 = \dfrac{1}{2}mv^2$

$2000= \dfrac{1}{2}mv^2$ ........(1)

now, speed of the car is doubled

v' = 2 v

$KE_2 = \dfrac{1}{2}mv'^2$

$KE_2 = \dfrac{1}{2}m(2v)^2$

from equation (1)

$KE_2 = 4\times \dfrac{1}{2}m(v)^2$

$KE_2 = 4\times 2000$

$KE_2 = 8000\ J$

Hence, the Kinetic energy would be equal to 8000 J.

The correct answer is option A.

8 0

2 years ago

The table shows the changes in velocity for several different cars. Each change takes place over a 10-second interval. Which car

sesenic [268]

Car B, Car C, And Car E Are either speeding up or slowing down

6 0

2 years ago

Read 2 more answers