Question

Q16: Which of the following statement is correct regarding velocity and
speed of a moving body?
(a) Velocity of a moving body is always higher than its speed
(b) Speed of a moving body is always higher than its velocity
(c) Speed of a moving body is its velocity in a given direction
(d) Velocity of a moving body is its speed in a given direction
Q17: When a car driver travelling at a speed of 10 m/s applies brakes and
brings the car to rest in 20 s, then the retardation will be:
(a) + 2 m/s?
(b) - 2 m/s2
(c) - 0.5 m/s?
(d) + 0.5 m/s²​

Answer 1

Answer:

Q16: d) Velocity of a moving body is it's speed in a given direction

Q17: d) + 0.5 m/s^2

Explanation :

Q16 : velocity is never higher than speed so first option is wrong speed is also not always higher than velocity it can be equal to it so second option is wrong speed is not velocity with direction so 3rd option is also wrong while velocity is speed with direction therefore option d is correct

Q17:

given,

u = 10 m/s

v = 0 m/s ( as it comes to rest )

t = 20 s

a = v - u / t

0 - 10/ 20

- 0.5 m/s^2

retardation is negative acceleration

so

- a = - ( - 0.5 m/s^2 )

- a = + 0.5 m/s^2

so option d is correct