(b) Which statement about beta radiation is true?

A car of mass m accelerates from speed v_1 to speed v_2 while going up a slope that makes an angle theta with the horizontal. Th

Karo-lina-s [1.5K]

Answer:

Work done by external force is given as

$Work_{external} = mgLsin\theta + \mu mgLcos(\theta) + \frac{1}{2}mv_2^2 - \frac{1}{2}mv_1^2$

Explanation:

As per work energy Theorem we can say that work done by all force on the car is equal to change in kinetic energy of the car

so we will have

$Work_{external} + Work_{gravity} + Work_{friction} = \frac{1}{2}mv_2^2 - \frac{1}{2}mv_1^2$

now we have

$W_{gravity} = -mg(Lsin\theta)$

$W_{friction} = -\mu mgcos(\theta) L$

so from above equation

$Work_{external} - mgLsin\theta - \mu mgLcos(\theta) = \frac{1}{2}mv_2^2 - \frac{1}{2}mv_1^2$

so from above equation work done by external force is given as

$Work_{external} = mgLsin\theta + \mu mgLcos(\theta) + \frac{1}{2}mv_2^2 - \frac{1}{2}mv_1^2$

8 0

3 years ago

A ball held above the floor has what type of energy?

kondaur [170]

Answer: I think the answer is B. Potential energy

Explanation:

Because the higher the ball is held up the more energy it has.

I hoped I really helped out. ;)

7 0

2 years ago

Read 2 more answers

A block of wood of mass 24 kg floats on water. The volume of the block below the surface of the water and the density of the woo

Slav-nsk [51]

Answer:

0.024m^3

Explanation:

=======

Answer:

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Given:-

Mass of the block of wood = 24 kg

Volume of wood = 0.032 m^3

Density of water = 1000kg/m^3

Now,

Density of wood is given by,

\frac{m}{v} = \frac{24}{0.032} \\

\frac{m}{v} = 750 \: kg/m ^{3}

Therefore,

The density of wood is 750kg/m^3

By principle of floatation,

Mass \:of\: wood = Mass\: of\: liquid \:displaced

Therefore,

Mass of liquid displaced = 24kg

Volume of liquid displaced (v),

\frac{m}{v} = \frac{24}{1000} \\

\frac{m}{v} = 0.24m ^{3}

Now,

Since the volume of the wood is equal to the volume of water displaced, it is 0.024m^3

=====

Note:

=====

=> The volume of the wood below the water surface is the volume of water displaced.

=> Buoyant\: force = Weight\: of\: the \:displaced\: water.

8 0

2 years ago

A jet with mass m = 5 × 104 kg jet accelerates down the runway for takeoff at 1.9 m/s2. What is the net vertical force on the ai

OLEGan [10]

The first sentence got me all psyched up to answer the question "What
horizontal force do the engines generate in order to accelerate it ?".

But the actual question, in the second sentence, turned out to be
a completely different one.

When the plane levels off and continues on at a constant altitude, it's
not accelerating up or down, so the net vertical force on it is zero.
The lift generated by the wings is exactly balancing the downward
force of gravity on the airplane.

3 0

3 years ago

Explain why if a perfume is released in a vacuum into the diffuse slowly

Tomtit [17]

Ummm I think you worded your sentence wrong or somethin cause that don’t make sense at all

5 0

2 years ago