What is the formula for calculating speed?

• v = t * d

• v = d * t

• v= t / d

• v = d / t

Answer explanation

The correct formula for calculating speed (v) is v = d / t, where d is distance and t is time. This means speed is the distance traveled divided by the time taken.

Which of the following is a vector quantity?

• Time

• Velocity

• Distance

• Speed

Answer explanation

Velocity is a vector quantity because it has both magnitude and direction, unlike time, distance, and speed, which are scalar quantities that only have magnitude.

How is speed usually measured?

• In metres per hour (m/h) or kilometres per second (km/s)

• In feet per second (ft/s) or miles per hour (mph)

• In metres per second (m/s) or kilometres per hour (km/h)

• In centimetres per minute (cm/min) or millimetres per week (mm/week)

Answer explanation

Speed is commonly measured in metres per second (m/s) or kilometres per hour (km/h), which are standard units in the metric system, making this the correct choice. Other options are less commonly used.

What is the average speed of a snail that takes 10 minutes to cross an 80 cm paving stone?

• 8 cm/min

• 80 cm/min

• 0.8 cm/min

• 800 cm/min

Answer explanation

To find the average speed, divide the distance by time. The snail crosses 80 cm in 10 minutes. Thus, average speed = 80 cm / 10 min = 8 cm/min. Therefore, the correct answer is 8 cm/min.

What is the conversion factor from km/h to m/s?

• Multiply by 1.6

• Divide by 3.6

• Multiply by 3.6

• Divide by 1.6

Answer explanation

To convert from km/h to m/s, you divide by 3.6. This is because 1 km is 1000 meters and 1 hour is 3600 seconds, so 1000/3600 simplifies to 1/3.6.

If a car travels 220 km in 2 hours, what is its average speed?

• 110 km/h

• 220 km/h

• 55 km/h

• 440 km/h

Answer explanation

To find the average speed, divide the distance by the time. Here, 220 km ÷ 2 hours = 110 km/h. Thus, the average speed of the car is 110 km/h.

What is the stopping distance of a car?

• The distance covered in one second

• The distance covered before the brakes are applied

• The distance covered after the brakes are applied

• The sum of reaction distance and braking distance

Answer explanation

The stopping distance of a car is the total distance it travels from the moment the driver perceives a need to stop until the car comes to a complete stop. This includes both the reaction distance and the braking distance.

What is the difference between speed and velocity?

• Both are vector quantities

• Both are scalar quantities

• Speed is vector, velocity is scalar

• Speed is scalar, velocity is vector

Answer explanation

Speed is a scalar quantity, meaning it only has magnitude (how fast an object is moving), while velocity is a vector quantity, which includes both magnitude and direction (how fast and in which direction an object is moving).

What is the unit of speed in the International System of Units (SI)?

• Miles per hour (mph)

• Feet per second (ft/s)

• Kilometres per hour (km/h)

• Metres per second (m/s)

Answer explanation

The unit of speed in the International System of Units (SI) is metres per second (m/s). This is the standard unit used for measuring speed in scientific contexts, unlike the other options which are not SI units.

Which of the following is not a unit of speed?

• Kilometres per hour (km/h)

• Joules per second (J/s)

• Miles per hour (mph)

• Metres per second (m/s)

Answer explanation

Joules per second (J/s) is a unit of power, not speed. The other options (km/h, mph, m/s) are all units that measure speed, indicating how far an object travels in a given time.