Question

10. The rear view mirror of a car is a plane mirror. A driver is reversing
his car at a speed of 2 m/s. The driver sees in his rear view mirror
the image of a truck parked behind his car. The speed at which the
image of the truck appears to approach the driver will be:
1 m/s (1) 2m/s
(iii) 4m/s (iv) 8m/s
hn​

Answer 1

Answer:

4 m/s

Explanation:

In a plane mirror, the object and it's image always remain at the same distance from the mirror. So, when the car reverses at a speed of 2 m/s, then the image will also appear to move towards the mirror at the same speed of 2 m/s. So, the speed at which the image of truck appears to approach the car driver will be 2 m/s + 2 m/s = 4 m/s.

Answer 2

Answer: ⤵️

(iii) 4 m/s

Explanation: ⤵️

The speed of the car is 2 m/s which means the car is approaching the truck with a speed of 2 m per second. The distance between the car and truck will decrease at a double rate. This is because the image of the truck will travel a distance twice the distance travelled by the car in equal time. Hence, the image of the truck will appear to approach the driver with the speed of 2 ×2 = 4 m/s.