A Scion iQ model car that weighs 860 kg takes 102 seconds to

A Scion iQ model car that weighs 860 kg takes 10.2 seconds to reach 27.8 m/s from being stationary. Assume that the acceleration is constant during this time. The vehicle travels 140 meters in that time. i) What is the value of the acceleration? ii) Determine the force that must be provided by the engine (in Newtons). iii) How much work (Joules) is done by the engine during the 10.2 second period?

Solution

ans 6

(a) Acceleration

Step 1: Formula v=u+at

v=final velocity

u=initial velocity

a=acceleration

t=time

or, a=(v-u)/t

Step 2: calculation

Here u=0 m/s, v=27.8 m/s, t=10.2 s

Hence a=2.73 m/s²

^{Ans (b)}

Step1 : formula for force:

Force F=mass (m) X acceleration (a)

step 2: calculation

here m= 860 Kg (given in the problem) and a=2.73 m/s² ( as found in ans a)

Hence F=860 Kg X 2.73 m/s²= 2347.8 N

Step1:Formula

Work done (W) = force(F) X displacement(d)

Step 2: calculation

Here F=2347.8 N( as found in ans b) and d=140 m (given in the problem)

hence W= 2347.8 N X 140 m = 328692 J

v=