Page 178 - Physics

Physics for Secondary Schools

If the dots are not equally spaced, then the
Acti vity 8.2
toy is accelerating at that time.
Aim: To determine the acceleration Direction
of a toy car using a ticker-
timer.
Materials: Toy car, ticker-timer, paper Figure 8.8: Dots showing acceleration
tape, remote-control device,
stopwatch In Figure 8.8, the interval between two
dots is increasing, this means that the
Procedure toy is accelerating. The velocity can
1. Attach a paper tape onto the toy car. be calculated by measuring the length
2. Pass the tape through the ticker- covered by 8 dots.
timer (see Figure 8.7). Acceleration is a fundamental concept in

Ticker-timer physics that describes the rate at which an
Toy car object changes its velocity. Acceleration
can occur due to a change in speed,
direction, or both. If an object is speeding
Tape up, it is said to be accelerating. If it is
slowing down, it is decelerating, which
is also a form of acceleration but in the
Figure 8.7
opposite direction.
3. Set the toy car in motion down
an inclined plane as in Figure 8.7 A simple example of acceleration can be
using a remote-control device. observed in a car. When you press the gas

4. Record the starting time using the pedal, the car speeds up - it accelerates.
When you press the brake pedal, the car
stopwatch. slows down - it decelerates. The steering
5. Press the remote-control device to wheel allows the car to change direction,
stop the toy car after one minute. which is another form of acceleration.

6. Record the fi nal stopping time. Change in velocity, ∆v
Acceleration, a =
Questions Time taken, t
(a) What did you observe when
the car was set in motion? Acceleration, a = Δv = v−u , where u
t
t
(b) Measure the interval between is the initial velocity and v is the fi nal
the marked dots. velocity.
(c) Calculate the initial and fi nal
velocities of the toy car. The SI unit of acceleration is metre per
2
(d) What is the acceleration of the second square, in short m/s .
car? The acceleration of an object can be
(e) Explain your results. positive or negative. If the acceleration is
in the same direction as the velocity, the

172
Student’s Book Form One

Physics Form 1 Final.indd 172 16/10/2024 20:58