In order to accelerate the dragster at a speed

, 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

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:

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

:

So, the power delivered by the engine is the total work divided by the time, t=7.30 s:

And since 1 horsepower is equal to 746 W, we can rewrite the power as
I'll go ahead and answer the ones here without an answer. For reference, the half-life formula is <em>final amount = original amount(1/2)^(time/half-life)</em>
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4) 12.5g
x = 100(1/2)^(63/21)
5) 50g
3.125 = x(1/2)^(0.1/0.025)
6) 500g
x = 4000(1/2)^(525/175)
7) 0.24g
0.06 = x(1/2)^(11430/5730)
8) 125g
x = 1000(1/2)^(17100/5700)
Hope this helps! :)
Answer:
Positively charged particle trajectories always follow electric field lines because the electric force on a positively charged particle is in the same direction as the electric field.
Explanation:
For any positive charge the electric field emerges radially outwards and it goes radially inwards for the negative charges.
- From the theory of electric field lines we know that they never intersect each other, either they get merged when the sources are unlike or they repel when the sources are alike. In other words the electric field lines align in the same direction as that of the field.
- So, when a positive charge is released into the an electric field they follow the direction of the field lines because they too have their field lines emerging radially outwards and hence these lines align in the direction of the field.
Answer:
Speed is a "scalar" quantity
(C) is the correct answer
An object could travel at 10 m/s to some point and then return to the origin at 10 m/s for an average speed of 10 m/s, however it's displacement over that time would be zero for a net velocity of zero.