A
The tendency of an object to resist a change in its motion.
Inertia
Which of Newton’s laws of motion is best illustrated in the situtation below:
A swimmer pushes water backward and moves forward.
Law of Interaction
The rate of change of velocity
Acceleration
Which of Newton’s laws of motion is best illustrated in the situtation below:
When a moving tray suddenly stops, a ball on it continues moving forward.
Law of Inertia
According to Newton’s first law, what happens to a moving object when the net forceon it is zero?
A. It continues moving at constant velocity
B. It immediately stops
C. It speeds up continuously
D. It changes direction continuously
A. It continues moving at constant velocity
What formula represents Ohm’s law?
I= V ÷ R
What is the complete name of Qatar’s electricity and water corporation?
Qatar General Electricity and Water Corporation
What is the action force of the situation:
A water-bottle rocket launches upward as water is expelled downward.
The rocket pushing the water downward.
In a metal wire, which particles move through the wire to produce electric current?
Electrons
Define electric current
Electric current is the rate at which electric charge flows through a conductor. It is measured in amperes (A).
This refers to the opposition to the flow of electric current
Resistance
What is the reaction force of the situation:
A water-bottle rocket launches upward as water is expelled downward.
Water pushing the rocket upward
Four objects are at rest on the classroom floor. Which object has the greatest inertia?
A. A 0.5 kg ball
B. A 2 kg chair
C. A 5 kg box
D. A 10 kg table
D
True or False: Current is inversely proportional to voltage and directly proportional to resistance
False
A lamp receives 120 C of electric charge in 20 seconds. What is the electric current flowing through the lamp?
6 A
The energy transferred per unit of electric charge between two points in a circuit.
Voltage
The acceleration of an object is ______________to the net force acting on it and _____________to its mass.
Directly proportional ; inversely proportional
Your family in Qatar is buying an electric fan. Two models operate at the same voltage, but one draws more current than the other. At the shop, you notice that the display fan has a damaged power cord, yet the salesperson suggests switching it on to test it.
If both fans operate at the same voltage, which has the higher effective resistance; the fan drawing more current or the one drawing less? Explain using the relationship among voltage, current, and resistance.
The fan drawing less current has the higher effective resistance. According to Ohm’s law, R = V/I. When voltage stays the same, resistance and current are inversely related: higher resistance results in less current, while lower resistance results in more current.
4. Two carts have the same mass. Cart X is at rest, while Cart Y moves in a straight line at constant speed. If the net force on each cart is zero, which statement is correct?
A. Cart Y has greater inertia because it is moving.
B. Cart X has greater inertia because it is at rest.
C. Both have equal inertia; Cart X stays at rest, and Cart Y continues at constant velocity.
D. Both have equal inertia, but Cart Y eventually stops because no net force keeps it moving.
C. Both have equal inertia; Cart X stays at rest, and Cart Y continues at constant velocity.
A resistor connected across a 24 V source carries a current of 3 A. What is its resistance?
8 Ω
What net force is needed to accelerate a 500 kg trolley at 15 m/s²?
7500 N
An object accelerates at 15 m/s² when a net force of 80 N acts on it. What is its mass?
5.33 kg
A lamp receives 240 C of electric charge in 5 mins. What is the electric current flowing through the lamp?
0.8 A
A resistor has a resistance of 8 Ω, and a current of 3 A flows through it. What is the voltage across the resistor?
24 V
A resistor draws 15 A when connected across a 12 V battery. It is then connected across a 24 V battery, and its resistance is doubled. What is the new current?
15 A