a ball is dropped from a tall building . after 1 sec another ball is dropped from the same point . Their distance of seperation after next 2 s
(a) 24.5m
(b) 49m
(c) 20m
(d) 20√2m
Answers
Answer:
24.5 is your correct qnswer
Answer:
2.1 You can use the formulae v u at and s ( u_____ v
2
)t for a particle moving in a
straight line with constant acceleration.
You need to learn this list of symbols and what they represent.
s displacement (distance)
u starting (initial) velocity
v fi nal velocity
a acceleration
t time
Displacements, velocities and accelerations have directions as well as sizes (or magnitudes).
You can derive the formulae for motion in a straight line with constant acceleration.
• acceleration
change in velocity _________________
change in time • distance moved average speed time
a
_____ v u
t average speed
_____
u v
2
v u at s ( ______
u v
2 )t
For an object moving horizontally, the positive direction is
usually taken as left to right. The starting point of an object
is usually taken as the origin from which displacements are
measured.
1 A particle is moving in a straight line with constant acceleration 3 m s2. At time t 0, the
speed of the particle is 2 m s1. Find the speed of the particle at time t 6 s.
2 A particle is moving in a straight line with constant acceleration. The particle passes a point
with speed 1.2 m s1. Four seconds later the particle has speed 7.6 m s1. Find the acceleration
of the particle.
3 A car is approaching traffi c lights. The car is travelling with speed 10 m s1. The driver applies
the brakes to the car and the car comes to rest with constant deceleration in 16 s. Modelling
the car as a particle, fi nd the deceleration of the car.
4 A particle moves in a straight line from a point A to point B with constant acceleration. The
particle passes A with speed 2.4 m s1. The particle passes B with speed 8 m s1, fi ve seconds
after it passed A. Find the distance between A and B.
5 A car accelerates uniformly while travelling on a straight road. The car passes two signposts
360 m apart. The car takes 15 s to travel from one signpost to the other. When passing the
second signpost, it has speed 28 m s1. Find the speed of the car at the fi rst signpost.
6 A particle is moving along a straight line with constant deceleration. The points X and Y are
on the line and XY 120 m. At time t 0, the particle passes X and is moving towards Y
with speed 18 m s1. At time t 10 s, the particle is at Y. Find the velocity of the particle at
time t 10 s.
7 A cyclist is moving along a straight road from A to B with constant acceleration 0.5 m s2.
Her speed at A is 3 m s1 and it takes her 12 seconds to cycle from A to B. Find a her speed at
B, b the distance from A to B.
8 A particle is moving along a straight line with constant acceleration from a point A to a
point B, where AB 24 m. The particle takes 6 s to move from A to B and the speed of the
particle at B is 5 m s1. Find a the speed of the particle at A, b the acceleration of the particle.
9 A particle moves in a straight line from a point A to a point B with constant deceleration
1.2 m s2. The particle takes 6 s to move from A to B. The speed of the particle at B is 2 m s1
and the direction of motion of the particle has not changed. Find a the speed of the particle
at A, b the distance from A to B.
10 A train, travelling on a straight track, is slowing down with constant deceleration 0.6 m s2.
Step-by-step explanation: