Question

a car falls off a ledge a drop to the ground in 0.7s what is the speed on striking in the ground
options:
a. 7m/s
b. 14 m/s
c. 0.7 m/s
d. 1.4 m/s

guys please help me out!!
​

Answer 1

ANSWER

Given,

time taken=0.5s

g=10ms

−2

As the car is under free fall, the initial speed is zero.

(a) Under free fall,

u=0

a=g

v=u+at

v=0+10×0.5

v=5ms

−1

(b) Average speed =

2

u+v

=

2

0+5

=2.5ms

−1

(c) From newton's equation of motion, As u=0,

h=ut+

2

1

gt

2

When h is the height, t is the time of free fall, g is the acceleration due to gravity. Putting the values in the above equation, we get

h=

2

1

×10×(0.5)

2

=5×0.25=1.25m