A scientist performs an experiment and asks other scientists around the

A 500 kg dragster accelerates from rest to a final speed of 100 m/s in 400 m (about a quarter of a mile) and encounters an avera

Fantom [35]

In order to accelerate the dragster at a speed $v_f = 100 m/s$ , its engine must do a work equal to the increase in kinetic energy of the dragster. Since it starts from rest, the initial kinetic energy is zero, so the work done by the engine to accelerate the dragster to 100 m/s is
$W= K_f - K_i = K_f = \frac{1}{2}mv_f^2=2.5 \cdot 10^6 J$

however, we must take into account also the fact that there is a frictional force doing work against the dragster, and the work done by the frictional force is:
$W_f = F_f d = -(1200 N)(400 m)= -4.8 \cdot 10^5 J$
and the sign is negative because the frictional force acts against the direction of motion of the dragster.

This means that the total work done by the dragster engine is equal to the work done to accelerate the dragster plus the energy lost because of the frictional force, which is $-W_f$ :
$W_t = W + (-W_f)=2.5 \cdot 10^6 J+4.8 \cdot 10^5 J=2.98 \cdot 10^6 J$

So, the power delivered by the engine is the total work divided by the time, t=7.30 s:
$P= \frac{W}{t}= \frac{2.98 \cdot 10^6 J}{7.30 s}=4.08 \cdot 10^6 W$

And since 1 horsepower is equal to 746 W, we can rewrite the power as
$P=4.08 \cdot 10^6 W \cdot \frac{1 hp}{746 W} =547 hp$

3 0

3 years ago

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Cora, an electrician, wraps a copper wire with a thick plastic coating. What is she most likely trying to do?

alukav5142 [94]

The correct answer among the choices given is the last option. Cora wrapping the copper wire with a thick plastic coating keeps a current from passing out a wire. The plastic wire here serves as an insulator. An insulator is a material that prevents electricity or current to flow out the circuit. In order to lessen the loss of energy.

HOPE THIS HELPS!

6 0

3 years ago

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What voltage produces a current of 50 amps with a resistance of 20 ohms?<br>

PIT_PIT [208]

Answer:

1000 V

Explanation:

Ohm's law:

V = IR

V = (50 A) (20 Ω)

V = 1000 V

5 0

3 years ago

Which term describes the number of crests that pass a point in a given amount of time

joja [24]

The term is frequency.

The frequency is the number of vibrations per unit of time or the number of waves that passes a point per unit of time.

Every crest (and every trough) represents a pass of the wave so you can count the number of crests in an intervavl of time to find the frequency as the number of crests divided by the time elapsed.

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3 years ago

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Why does rhododendron not grow well in the terai region of nepal give reason

Andrews [41]

Answer:

Tge Rhododendrob is the national flower of Nepal. The hills and mountain sides ranges of Nepal are decorated with diff colours and shapes

3 0

2 years ago