A motorcycle is stopped at a traffic light. When the light turns green, the motorcycle accelerates to a speed of 91 km/h over a distance of 47 m. (a) What was the average acceleration of the motorcycle over this distance?

? m/s2

(b) Assuming the motorcycle maintained a constant acceleration, how far is it from the traffic light after 3.3 s?

? m

Given :

Initial speed , u = 0 m/s .

Final speed , v = 91 km/h = 25.28 m/s .

To Find :

a) Average acceleration .

b ) Assuming the motorcycle maintained a constant acceleration, how far is it from the traffic light after 3.3 s .

Solution :

a )

We know ,by equation of motion :

b)

Also , by equation of motion :

Hence , this is the required solution .

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27

i think the answer is a, hope this : )