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3 years ago

What is the kinetic energy of an object that has a mass of 50.0kg and a velocity of 18 m/s?

Physics

1 answer:

Rom4ik [11]3 years ago

7 0

<h2>Answer </h2>

The kinetic energy is 8100 J.

<u>Explanation</u>

Mass is 50.0kg and velocity is 18 m/s, the kinetic energy is:

As we know the formula of kinetic energy which is K.E = ½ ( mv ^ 2 ),

mass = m = 50.0kg

velocity = v = 18 m / s,

by putting values in the formula,

K.E = ½ ( mv ^ 2 ),

K.E = ½ ( 50kg ) . ( 18 m / s ) ^ 2

K.E = ½ ( 50kg ) . ( 324 ),

=> K.E = 1/2 ( 16200 ),

=> K.E = 16200 / 2,

=> K.E = 8100J.

Hence, the kinetic energy ( K.E ) is 8100 joule ( J ).

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Which of the following graphs shows the relationship between two variables that obey the inverse square law?

blondinia [14]

Well, if we've been paying attention in class, we already KNOW that the electrostatic force changes as the inverse square of the distance, and the top graph is conveniently labeled "Electrostatic Force".

But if we didn't already know that, we'd have to examine the graphs, and find the one where 'y' changes like 1/x² .

The top graph does that. After 1 unit of time, the force is 350. Double the time to 2 units, and the force should drop to 1/4 of 350 ... sure enough, it's a little less than 90. Double the time again, to 4 units, and it should drop to 1/4 of a little less than 90 ... by golly, it's down below 30.

The first graph is what an inverse square looks like. Now that you've worked out this graph, you'll know an inverse square relationship whenever you see it.

8 0

3 years ago

In fig. 2-27, a red car and a green car, identical except for the color, move toward each other in adjacent lanes and parallel t

lbvjy [14]

Answer:

a) V₀ = 13.5m/s

b) a = 2.1 m/s²

Explanation:

1) Convert velocities to m/s

i) 20 km/h × 1000m/kg × 1h/3600s = 5.556m/s

ii) 40km/h = 11.111m/s

2) Red car, time elapsed to reach position x = 44.5m

Constant velocity ⇒ x = V×t ⇒ t = x / V

⇒ t₁ = 44.5m / 5.556m/s = 8s

3) Red car, time elapsed to reach position x = 77.6m

t₂ = 76.6m / 11.111/s = 6.9s

4) Green car, distance run at t₁ = 8s, x = 44.5m

i) uniform acceleration equation d = V₀t + at² / 2

ii) d = 220m - x = 220m - 44.5m = 175.5m = V₀ (8) + a (8)² /2

175.5 = 8V₀ + 32a ↔ equation (1)

5) Green car, distance run at t₂ = 6.9s, x = 76.6m

i) d = 220m - x = 220m - 76.6m = 143.4

ii) 143.4 = V₀t₂ + at₂² / 2

143.4 = V₀ (6.9) + a(6.9)² / 2

143.4 = 6.9V₀ + 23.8a ↔ equation (2)

6) Solve the system of equations:

175.5 = 8V₀ + 32a ↔ equation (1)

143.4 = 6.9V₀ + 23.8a ↔ equation (2)

V₀ = 13.5m/s

a = 2.1 m/s²

5 0

4 years ago

Read 2 more answers

Which forms of energy are involved when you turn on a desk lamp and the bulb<br> becomes hot?

alukav5142 [94]

Answer:

Electric energy moves through the wire to the lamp's bulb. In the bulb, electric energy transforms into thermal energy and light energy.

Explanation:

4 0

3 years ago

Problem #3: 3.6. A diode has wdo = 0.4 µm and φj = 0.85 V. (a) What reverse bias is required to triple the depletion-layer width

Alchen [17]

Answer:

a) 6.8 Volt

b) 1.21Цm

Explanation:

We are given from the question that

The zero -bias depletion layer width( $W_{do}$ ) is 0.4Цm

The built in voltage φj is 0.85V

Now to calculate the reverse voltage( $V_{R}$ ) that would be required to triple the depletion - layer width.

The depletion - layer width ( $W_{d}$ ) of the diode has the formula

$W_{d} = W_{do} \sqrt{1 + \frac{V_{R} }{Qj} }$

For three times of $W_{d}$ we have

$3W_{d} = W_{do} \sqrt{1 +\frac{V_{R} }{Qj} }$

=> $\frac{V_{R} }{Qj} = 3^{2} -1$

=> $V_{R} = 8Qj$

Substituting value of φj

We have

$V_{R} = 8(0.85V)$

= 6.8 V

The required bias voltage $V_{R}$ is 6.8 V

The solution for the b part of the question is uploaded on first image

7 0

3 years ago

A uniform metal tube of length 5m and mass 9kg is suspended by two vertical wires attached at 50cm and 150cm respectively from t

Elena-2011 [213]

Answer:

force (tension) of 29.4 N (upward) in 100 cm

force (tension) of 58.4 N (upward) in 200 cm

Explanation:

Given:

Length of tube = 5 m (500 cm)

Mass of tube = 9

Suspended vertically from 150 cm and 50 cm.

Computation:

Force = Mass × gravity acceleration.

Force = 9.8 x 9

Force = 88.2 N

So,

Upward forces = Downward forces

D1 = 150 - 50 = 100 cm

D2 = 150 + 50 = 200 cm

And F1 = F2

F1 x D1 = F2 x D2

F1 x 100 = F2 x 200

F = 2F

Total force = Upward forces + Downward forces

3F = 88.2

F = 29.4 and 2F = 58.8 N

force (tension) of 29.4 N (upward) in 100 cm

force (tension) of 58.4 N (upward) in 200 cm

4 0

4 years ago