Grade 9 Physics Final Exam

Two cities report their temperatures as 0°C and 32°F, respectively. What conclusion can you draw from this information?

• The first city is colder than the second

• The second city is colder than the first

• It's impossible to compare temperatures in different scales

• Both cities have the same temperature

Which of the following is a common characteristic of all waves?

• They all require a medium to travel through.

• They all require a source of electricity to be generated.

• They all move at the same speed.

• They all transfer energy without transferring matter.

Why does a longer ramp make it easier to push a heavy object up to a higher place?

• It increases the weight of the object

• It spreads the effort over a longer distance

• It reduces the amount of work required

• It uses gravity to help lift the object

In a simple pendulum, what is the primary factor that determines the period of oscillation?

• The mass of the pendulum bob

• The amplitude of the swing

• The length of the string

• The temperature of the environment

If the efficiency of the pulley system in Figure below is 80%, then what is the AMA of the pulley system?

• 4

• 3.2

• 3.6

• 5

An echo was received after 3seconds by a sonar system to find a wrecked ship on the sea bed. If the speed of sound in the sea water is 1500m/s. How high is the ship?

• 3000m

• 1000m.

• 4500m

• 2250m

Which simple machine is commonly used in an office chair to allow easy movement across the floor?

• Pulley

• Wedge

• Wheel and axle

• Lever

What is speed of sound in air at temperature 50°C?

• 392m/s

• 343m/s

• 361m/s

• 142m/s

Force multipliers simple machines is occurs when,

• Force of load is greater than force of effort

• Distance moved by load is greater than distance moved by effort

• Force of effort is greater than force of load

• Distance moved by load is equal to distance moved by effort

If the velocity ratio (VR) of a machine is 3, and the mechanical advantage (MA) is 2, what can be said about the efficiency of the machine?

• The machine is 100% efficient

• The machine is more efficient than ideal

• The machine is less efficient than ideal, with some energy lost

• The machine has 0% efficiency