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3 years ago

Which has the larger kinetic energy, a 10 g bullet fired at 400 m/s or a 80 kg bowling ball rolled at 6.5 m/s ?

1 answer:

7 0

Formulae for Kinetic energy is:
Kinetic Energy= 1/2xmassx(velocity)^2

For comparison we need to have same units,thus we convert 10g into Kg.
10g/1000=0.01Kg

Input the value of bullet in the formulae;
Kinetic Energy= 1/2x0.01kgx(400)^2
K.E=800J

Input value of the ball:
Kinetic Energy=1/2x80kgx(6.5)^2
K.E=1690J

Which means that th Energy of the ball is more than the bullet.

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A certain light truck can go around a flat curve having a radius of 150 m with a maximum spee dof 32.0 m/s. With what maximum sp

Dvinal [7]

Answer

Maximum speed at 75 m radius will be 22.625 m /sec

Explanation:

We have given radius of the curve r = 150 m

Maximum speed $v_{max}=32m/sec$

Coefficient of friction $\mu =\frac{v_{max}^2}{rg}=\frac{32^2}{150\times 9.8}=0.6965$

Now new radius r = 75 m

So maximum speed at new radius $v_{max}=\sqrt{\mu rg}=\sqrt{0.6965\times 75\times 9.8}=22.625m/sec$

7 0

2 years ago

You stand on top a building 44 m tall with a water balloon. You drop the water balloon from rest. How fast is the balloon moving

Alecsey [184]

<h2>The balloon is moving when it is halfway down the building at 20.78 m/s.</h2>

Explanation:

We have equation of motion v² = u² + 2as

Initial velocity, u = 0 m/s

Acceleration, a = 9.81 m/s²

Displacement, s = 0.5 x 44 = 22 m

Substituting

v² = u² + 2as

v² = 0² + 2 x 9.81 x 22

v² = 431.64

v = 20.78 m/s

Velocity at 22 m = 20.78 m/s

The balloon is moving when it is halfway down the building at 20.78 m/s.

7 0

3 years ago

A food department is kept at â12Â°c by a refrigerator in an environment at 30Â°c. the total heat gain to the food department is

slava [35]

As per energy conservation in the reversible engine we can say

$Q_2 + W = Q_1$

here we know that

$Q_2 = 3300 kJ/h$

$Q_1 = 4800 kJ/h$

now from above equation

$3300 + W = 4800$

$W = 1500 kJ/h$

now we can convert it into kW

$W = 1500\times \frac{kJ}{3600s}$

$W = 0.42 kW$

so above is the power input to the refrigerator

now to find COP we know that

$COP = \frac{Q_2}{W}$

$COP = \frac{3300}{1500} = 2.2$

so COP of refrigerator is 2.2

3 0

2 years ago

Which two charges of a magnet will attract?

ale4655 [162]

Answer:

The other end is called the south pole. When two magnets are brought together, the opposite poles will attract one another, but the like poles will repel one another. This is similar to electric charges.

Explanation:

4 0

2 years ago

Read 2 more answers

If a wave has a wavelength of 9 meters and a period of 0.006, what is the velocity of the wave?

lana66690 [7]

<u>Answer</u>

D. 1,500 m/s

<u>Explanation</u>

the wave equation states that,

V = λf

Where V ⇒ Velocity

λ ⇒ wavelength

f ⇒ Frequency

F = 1/T

Where T ⇒ period

F = 1/0.006

= 166.667

∴ V = 9 × 166.667

= 1,500 m/s

4 0

3 years ago

Read 2 more answers