Question

can someone solve my physics assignment

Answer 1

Q1

when velocity changes at non uniform rate it is defined by the ratio of total displacement/ total time and when velocity changes at uniform rate it is given by the sum of initial +final velocity/2=u+v/2

Q2

DISTANCE=1384km
time=5 hrs
avg speed=d/t
=1384/5
=276.8km/hr

Q3

case1 s=30 km/hr
         t=30 min=1/2hr
       d=s*t=30*1/2=15 km
case2=s=25 km/hr
           t=1 hr
           d=s*t=25*1=25 km
case3=s=40 km/hr
            t=2 hrs
           d=s *t=40*2=80 km/hr
now..............
avg speed=total distance/total time
                =15+25+80/ 7/2
             =120/7*2 
               =17.1*2
                 =34.2 km/hr

Q4

TOTAL DISTANCE=120 km
case1 =d1=30 km
             s1=30 km/hr
           t1=d/s=1 hr
avg speed =total distance/total time taken
              60=120/t1+t2
              60t2=120-60=60
                 t2=60/60=1 hrs 

d2=90 km /hr
 t2=1 hr
s2=d/t=90/1=90 km/hr

Q5

U=0.5 m/s
a= --0.05 m/s^2
 v=0 m/s

by using 1st eq. of motion
v=u+at
0=0.5-0.05t(a is negative)
-0.5=-0.05t
cancelling minus sign and 0.5 by 0.05
t=10s

Q7 

Motion of MOON around EARTH is accelerated because although the speeds is uniform but velocity is not as the direction is changing continuously. 

Q8
Speed remains constant in circular motion

Q9
Direction changes continuously

Q10

v=0 m/s
t=25 s
a= -1.5 m/s^2
u=?
v=u+at
0=u-1.5*25
-u=-37.5
u=37.5 m/s

Q11
SPEEDOMETER

Q12
RETARDATION or DECCELERATION

Q13
POSITIVE ACCELERATION --If the acceleration is in the direction of velocity it is positive
NEGATIVE ACCELERATION--If the acceleration is in opposite  direction of velocity it is negative

Q14
 
a=v-u/t
  =m/s-m/s/s
  =m/s/s
  =m/s^2
hence derived ,si unit of acceleration =m/s^2

Q15
D=100 m
t=5 min=300s
avg speed=total distance/total time taken
                =100/300
                =1/3 m/s
now.........

1/3 m/s=1/3*18/5 km/hr
            =6/5 km/hr=1.2 km/hr