Physics about velocity?

Question

police car moving at 140kph chases a speeding car moving at 110kph.how much closer to the speeding car does the police car get each minute?

car A moving at 100kph is 80km away from car B moving at 60kph. how far does car A nid to travel to reach car B?

Answer 1

140 kph = 38.89 ms^-1

110 kph = 30.56 ms^-1

Police car gets -: 38.89 - 30.56 = 8 1/3 metres closer per second.

2nd bit-:

Difference in Velocity = 100 - 60 = 40 kph

If car B needs to catch up 80km.

80 / 40 = 2 hours for Car A to catch car B

Answer 2

In the first case the police car is closing at 140 - 110 = 30 kph

to convert to kpm. there are 60 min in a hour, so divide by 60. (to remember to multiply look at the units kilometers/hours*1 hour/60 minutes. The hours cancel and you have kilometers/min.)

30kph = 1/2 kilometers/min.

In the second case they are closing at 40kph. It is necessary to close 80km dividing it will take 2 hours.