Question

please answer with steps both
question​

Answer 1

Question 1):-A ball Hits horizontally with velocity of 6m/s.After wall it rebounds horizontally with velocity of 4.4m/s. if the balls remains in the contact of wall for 0.04sec. the acceleration of ball would be (take direction of initial velocity is positive)?

Solution:-

velocity of ball just before the time of collision=6m/s

This, velocity will be taken as initial velocity

velocity of ball just after collision = final velocity of the ball=-4.4m/s

{since,after collision the velocity of ball have opposite direction so it will be taken as negative}

time in which this change in velocity occur=.04s

now we know acceleration is the rate of change of velocity

a=(v-u)/T

a=(-4.4-6)/.04

acceleration=-10.4/.04=-260

acceleration=-10.4/.04=-260hence option 2) is correct

question 2;-a body covers half the distance with the speed of 20m/s and the other half 30m/s. The average speed of the body during the whole journey?

Solution:-let the total distance to be covered be x

time taken to travel half journey=x/2×20=x/40

time taken to travel other half journey=x/2×30=x/60

total time taken=(3x+2x)/120=5x/120=x/24

total distance travelled=x

average speed=total distance travelled/total time taken

Average speed=x/x/24=24

Average speed=x/x/24=24

Hence option b is correct

{hope it helps you}