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An electric toy car with a mass of #3 kg# is powered by a motor with a voltage of #4 V# and a current supply of #8 A#. How long will it take for the toy car to accelerate from rest to #5/3 m/s#?

Answer 1

Benjamin Asiedu

The time is #=0.13s#

Voltage is #U=4V#

Current is #I=8A#

The power is

#P=UI=4*8=32W#

Velocity is #v=5/3ms^-1#

Mass is #m=3kg#

The kinetic energy is

#KE=1/2mv^2=1/2*3*(5/3)^2=25/6J#

But,

#E=P*t#

The time is #t=E/P=(25/6)/32=0.13s#

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Answer 2

Isabella Alvarez

Time = (Final Velocity - Initial Velocity) / Acceleration Acceleration = Voltage × Current / Mass Time = (5/3 m/s - 0 m/s) / [(4 V × 8 A) / 3 kg]

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.