A car along with passengers weighs  2000 kg it accelerates from 36 km per hour to 90 km per hour in 10 seconds calculate a.acceleration b. Distance  covered by car while accelerating c. momentum of car after 10 second d.force developed by the engine of car e.Total energy expanded during accelerationf. power of the engine in Kilowatt

initial speed = 36 km/hr = 36×(5/18) = 10 m/s ; final speed = 90 km/hr = 90×(5/18) = 25 m/s

 

(a) acceleration ; formula to be used   :- " v = u+a t ",  acceleration a = (v-u)/t = (25-10)/10 = 1.5 m/s²  

 

(b) distance ; formula to be used :- " S = u t +(1/2) a t² " , distance = 10×10 + (1/2)×1.5×10×10 = 175 m

 

(c) momentum = mass × speed  = 2000×25 = 50000 Kgm/s

 

(d) force = mass × acceleration = 2000×1.5 = 3000 N

 

(e) Energy = workdone = force ×distance = 3000×175 = 5,25,000 J

 

(f) Power = Energy /time = 525000/10 = 52500 W = 52.5 kW