Question

When a car of mass 1167 kg accelerates from 10.0 m/s to some final speed, 4.00 × 105 j of work are done. find this final speed?

Answer 1

final speed = 28 m/s

Step-by-step explanation:

As per work energy theorem we know that

Work done on the object = change in kinetic energy

so here we have

`W = KE_f - KE_i`

now we will have

`W = 4.00 * 10^5 J`

also we know that

mass = 1167 kg

and initial speed is given as

`v_i = 10.0 m/s`

now from above work energy equation we will have

`4.00 * 10^5 = (1)/(2)1167(v_f^2) - (1)/(2)1167(10^2)`

`4.00 * 10^5 = (1)/(2)1167 v_f^2 - 58350`

`(1)/(2)(1167)v_f^2 = 4.00 * 10^5 + 58350`

`v_f = 28 m/s`

Answer 2

Using the theorem of Work and Energy:

m = mass of the car = 1167 Kg

V = Final Velocity of the car

v = initial velocity of the car = 10 m/s

Net Work Done = 1/2(mV^2 - mv^2)

4 x 10^5 = 0.5 x 1167 (V^2 - 10^2)

V= (458350/583.5)^1/2

= 28 m/s