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2 years ago

What is the efficiency of a car's engine when heat input is 400,000 joules and

Physics

2 answers:

Aleksandr-060686 [28]2 years ago

5 0

Either 25% or 75%. does it to how much is wasted or the difference in the input and waste?

otez555 [7]2 years ago

3 0

Answer: A. 25%

Explanation: Ap3x

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According to thomas gage's spies, in which town had the minutemen been collecting a large amount of arms?

Citrus2011 [14]

The correct answer for the given question above would be option B. CONCORD. According to Thomas Gage's spies, the town in which the minutemen had been collecting a large amount of arms is in Concord. The minutemen are civilian colonists who established an independent organization forming a well-prepared militia. Hope this answers your question.

7 0

3 years ago

Read 2 more answers

A ball is moving with a velocity of 0.5 m/s its velocity is decreasing at the rate of 0.05 m/s² what is its velocity in 5 second

Law Incorporation [45]

Answer:

v after 5s = 0.25 m/s, it took 10s to stop, it has traveled 2.5m before stopping

Explanation

We can use the equation of motion with constant acceleration

Given: v0= 0.5 m/s a= -0.05 m/s²

v(5s) = v0 + a×t = 0.25 m/s

Stop => v=0 => v0 + a×t = 0 => t=10s

Distance at t=10s ⇒ x(10) = 0.5×10 + 0.5x(-0.05)x10² = 2.5m

4 0

3 years ago

A 10n force is applied to a 25kg mass to slide it across a frictional surface. What is the acceleration of the mass?

klasskru [66]

Answer: a = 0.4m/s^2 - 9.8*c where c is the coefficient of kinetic friction of the surface

Explanation: We know that, by the second Newton's law, a = F/m

where a is the acceleration, F is the net force and m is the mass of the object.

Then, if the surface is frictionless, the total force applied in the object is 10N, and the mass of the object is 25kg, so the acceleration is:

a =10N/25kg = 0.4m/s^2.

But if the surface is frictional, there will be a force of friction applied in the mass (this depends on the coefficient of friction and the weight of the mass), this means that the acceleration will be reduced.

If = -(9.8*25)*c

where c is a number that is bigger than 0 and smaller than 1, is called the coefficient of kinetic friction.

So the total force is now:

F = (10 - 9.8*25*c)

Then, the acceleration in a frictional surface is equal to:

a = (10 - 9.8*25*c)/25 = 0.4m/s^2 - 9.8*c

6 0

3 years ago

Read 2 more answers

1. How can you explain the sound has energy?

LenKa [72]

Answer:

Sound energy is produced when an object vibrates. The sound vibrations cause waves of pressure that travel through a medium, such as air, water, wood or metal. Sound energy is a form of mechanical energy.

Explanation:

5 0

2 years ago

During electrical storms, a bolt of lightning can transfer 10 C of charge in 2.0 µs (the amount of time can vary considerably).

nydimaria [60]

Answer:

Explanation:

charge, q = 10 C

time, t = 2 micro second

Current, i = q / t

i = 10 / (2 x 10^-6) = 5 x 10^6 A

(a)

distance, d = 1 m

the formula for the magnetic field is given by

$B = \frac{\mu_{0}}{4\pi}\frac{2i}{d}$

$B = 10^{-7}\frac{2\times 5\times 10^{6}}{1}$

B = 1 Tesla

Now the distance is d' = 1 km = 1000 m

$B' = \frac{\mu_{0}}{4\pi}\frac{2i}{d}$

$B' = 10^{-7}\frac{2\times 5\times 10^{6}}{1000}$

B' = 0.001 Tesla

(b) The magnetic field of earth is Bo = 3 x 10^-5 tesla

B / Bo = 3.3 x 10^4

B'/Bo = 33.3

4 0

3 years ago