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2 years ago

8. A car initially has 100 J of total energy. After driving down the road, the car's

Physics

1 answer:

sveta [45]2 years ago

8 0

The work done on the car is -20 J.

Work done on the car is negative, meaning that the car actually does work on the external system.

<h3>Energy and law of conservation of energy</h3>

Energy is the ability to do work
the law of conservation of energy states that the total energy in a system is conserved

From the law of conservation of energy, the initial energy of the car before it moves down the road remains constant or unchanged.

Initial energy = 100 J
Initial energy = Final energy - work done on car
Final Energy = Work done on car + initial energy

80J = Work done on car + 100 J

Work done on car = 80 - 100J

Work done on car = -20 J

Hence, the work done on the car is -20 J

Work done on car is negative.

Since work done on the car is negative, it means that the car actually does work on the external system. Hence, the decrease in the energy of the car.

Learn more about energy and work at: brainly.com/question/13387946

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The Mass of the Sun is 1.989 × 10^30 kg. The speed of light is 3 x 10^8 m/s. Assuming the Sun is 75% hydrogen, how much Energy c

bogdanovich [222]

Answer:

$E = 13.428 \times 10^{46} J$

Explanation:

Mass of the Sun = $1.989 \times 10^{30} Kg$

Amount of Hydrogen = 75% of Mass of Sun,

thus mass of Hydrogen (m) in the Sun is,

$m = 1.989 \times 10^{30} \times \frac{75}{100}$

m = $1.492 \times 10^{30}$

Speed of Light (c) = $3 \times 10^{8} m/s$

Thus, energy(E) produced if whole of hydrogen is converted into energy,

E = mc²

$E = 1.492 \times 10^{30} \times (3 \times 10^{8} )^{2}$

$E = 1.492 \times 9 \times 10^{46}$

$E = 13.428 \times 10^{46} J$

8 0

3 years ago

Sonia O'Sullivan of Ireland set the World Record in 1994 for the Women's 1000 m race with a time of 2 minutes and 45 seconds. Wh

Aleks04 [339]

Answer:

Sonia O'Sullivan (born 28 November 1969) is an Irish former track and field athlete. She won a gold medal in the 5000 metres at the 1995 World Championships, and a silver medal in the 5000 metres at the 2000 Olympic Games.[1] Her 2000 m world record of 5:25.36, set in 1994 stood until 2017.[2]

O'Sullivan first came to prominence when winning the 1500 m at the 1991 Universiade, before going on to finish fourth in the 3000 m final at the 1992 Olympic Games. She then won a silver medal in the 1500 m at the 1993 World Championships. She was the favourite for the 5000 m title at the 1996 Olympic Games but dropped out of the final due to illness. As well as her 1995 World title, she won three gold medals at the European Championships, in the 3000 m (1994), 5000 m (1998) and 10,000 m (1998), and is a two-time World Cross Country Champion.

O'Sullivan won silver medals in the 5000 m and 10,000 m at the 2002 European Championships, and competed at her fourth Olympic Games in 2004. She is known for her dramatic kick, clocking 28-second final 200 m splits in some of her races.[3]

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you can find from here

5 0

3 years ago

Read 2 more answers

Find the acceleration of the blocks when the system is released. The coefficient of kinetic friction is 0.4, and the mass of eac

grin007 [14]

Answer:

a = 4.9(1 - sinθ - 0.4cosθ)

Explanation:

Really not possible without a complete setup.

I will ASSUME that this an Atwood machine with two masses (m) connected by an ideal rope passing over an ideal pulley. One mass hangs freely and the other is on a slope of angle θ to the horizontal with coefficient of friction μ. Gravity is g

F = ma

mg - mgsinθ - μmgcosθ = (m + m)a

mg(1 - sinθ - μcosθ) = 2ma

½g(1 - sinθ - μcosθ) = a

maximum acceleration is about 2.94 m/s² when θ = 0

acceleration will be zero when θ is greater than about 46.4°

8 0

3 years ago

A hungry 169169 kg lion running northward at 77.377.3 km/hr attacks and holds onto a 31.731.7 kg Thomson's gazelle running eastw

navik [9.2K]

Answer: 75,242.9 m/s

Explanation:

from the question we are given the following parameters

mass of Lion (ML) = 169,169 kg

velocity of lion (VL) = 777,377.7 m/s

mass of Gazelle (Mg) = 31,731.7 kg

velocity of Gazelle (Vg) = 63,863.8 kg

mass of Lion and Gazelle (M) = 200,900.7 kg

velocity of Lion and Gazelle (V) = ?

The first figure below shows the motion of the Lion and Gazelle with their direction.

The second diagram shows the motion of the Lion and Gazelle with their directions rearranged to form a right angle triangle.

from the triangle formed we can get the velocity of the Lion and Gazelle immediately after collision using their momentum and Phytaghoras theorem

momentum = mass x velocity

momentum of the Lion = 169,169 x 77,377.3 = 13,089,840,463.7 kgm/s

momentum of the Gazelle = 31,731.7 x 63,863.8 = 2,026,506,942.46 kgm/s

momentum of the Lion and Gazelle = 200,900.7 x V

now applying Phytaghoras theorem we have

13,089,840,463.7 + 2,026,506,942.46 = 200,900.7 x V

15,116,347,406.16 = 200,900.7 x V

V = 75,242.9 m/s

7 0

3 years ago

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A metal container with the oil weigh

MA_775_DIABLO [31]

Answer:

16 kg

Explanation:

M - container

m - oil mass

by definition of density ,

relative density is the ratio of the density of a substance to the density of water.

relative density = density/ density of water

density of oil = 1.2*1000 kgm⁻³ = 1200 kgm⁻³

1 Litre =10⁻³ m³

oil volume = 80 *10⁻³ m³

mass of oil = density * volume

= 1200*80*10⁻³

= 96 kg

Mass of container + mass of oil =112

mass of container = 112 - 96

= 16 kg

7 0

3 years ago