Question

Help me. Today I need this in my class. Plzzzzzzzzzzzzzzzzzzzzzzzzzzzzz help me

Answer 1

NOTE :

While changing from km/hr to m/s multiply with 5/18 .

Question i

Change in velocity = 90 km/hr - 36 km/hr

                                = 90 m/s × 5/18 - 36 × 5/18 m/s

                                = 5 × 5 m/s - 2 × 5 m/s

                                = 25 m/s - 10 m/s

                                = 15 m/s

Acceleration in m/s

Velocity / time

= 15 m/s / 20 s

= 3 / 4 m/s²

= 0.75 m/s²

Acceleration in km/hr

Velocity change = 90 - 36

= 54 km .

Time = 20 s

= 20 / 3600 hr

= 1 / 180 hr

Acceleration = 54 / 1 / 180

= 54 × 180 km/hr²

= 9720 km/hr²

Answer 2

you know that to change the speed from kilometre per hour into metre per second we need to multiply it with 5 by 18

Change in velocity = 90 km/hr - 36 km/hr

                                = (90 m/s × 5/18) - (36 × 5/18) m/s

                                =( 5 × 5) m/s - (2 × 5) m/s

                                = 25 m/s - 10 m/s

                                = 15 m/s


now we know that acceleration is given by velocity for unit time means rate of change of velocity acceleration is equals to velocity divided by time

= 15 m/s / 20 s

= 3 / 4 m/s²

= 0.75 m/s²


Acceleration in km/hr


Velocity change = 90 - 36

= 54 km /h


Time = 20 s

= 20 / 3600 h

= 1 / 180 h


Acceleration = 54 / 1 / 180

= 54 × 180 km/h^2

= 9720 km/h^2



hope it helps you ❤️❤️