Question

Example 10.2 A car falls off a ledge and
drops to the ground in 0.5 s. Let
g = 10 ms? (for simplifying the
calculations)
(1) What is its speed on striking the
ground?
(11) What is its average speed during the
1.5 s?
(iii) How high is the ledge from the
ground?​

Answer 1

Answer:

Time, t = 1/2 second

Initial velocity, u = 0 ms-¹

Acceleration due to gravity, g = 10 ms-²

Acceleration of the car, a = + 10 m-²

(downward)

i) speed v = at

v = 10 × 0.5

= 5 ms-1

ii) Average speed = u + v/2

= ( 0 ms-¹ + 5 ms-¹)/2

= 2.5 ms-¹

iii) distance travelled, s = 1/2 at²

= 1/2 × 10 ms-² × 0.25 s²

= 1.25 m