vivek mehto(roll no 43)

Q.During an experiment, a signal from a spaceship reached the ground station in five minutes. What was the distance of the spaceship from the ground station? The signal travels at the speed of light, that is, 3 × 10⁸ m s⁻¹.

Answer

Speed= 3 × 10⁸ m s⁻¹
Time= 5 min = 5 x 60 = 300 secs.

Distance= Speed x Time
Distance= 3 × 10⁸ m s⁻¹ x 300 secs. = 9 x 10¹⁰ m During an experiment, a signal from a spaceship Q.reached the ground station in five minutes. What was the distance of the spaceship from the ground station? The signal travels at the speed of light, that is, 3 × 10⁸ m s⁻¹.

Answer

Speed= 3 × 10⁸ m s⁻¹
Time= 5 min = 5 x 60 = 300 secs.

Distance= Speed x Time
Distance= 3 × 10⁸ m s⁻¹ x 300 secs. = 9 x 10¹⁰ m   

Q. A bus decreases its speed from 80 km h⁻¹ to 60 km h⁻¹ in 5 s. Find the acceleration of the bus.

Answer

Speed	Velocity
Speed is the distance travelled by an object in a given interval of time.	Velocity is the displacement of an object in a given interval of time.
Speed = distance / time	Velocity = displacement / time
Speed is scalar quantity i.e. it has only magnitude.	Velocity is vector quantity i.e. it has both magnitude as well as direction.