Average Speed and Velocity

65 km per hour North is an example of an objects _______

• speed.

• displacement.

• velocity.

Speed is different from velocity because

• Velocity has a direction.

• Speed uses Distance /Time

• Velocity doesn't include distance

An object travels a distance of 12.8 m in 15 seconds. What is its average velocity?

• 15 m/s
• 12.8 m/s
• 0.85 m/s
• 1.17 m/s

Find the velocity of a plane that traveled 3000 km west in 5 hours.

• 600 km/h

• 6 km/h west

• 600 km/h west

• 6000 km/h west

Tags

NGSS.MS-PS3-1

If a projectile is fired north 390m in 7.8s, what is its velocity?

• 50 m/s N

• 0.2 m/s N

• 312 m/s N

Average velocity is equal to average speed ___________.

• at all times.

• when the body moves in straight line with no change in direction.

• when the body moves in straight line with change in direction.

• when the body moves along a circular path

If a body starts from a point and returns back to the same point, then its

• average speed is zero, but average velocity is not zero.

• both average speed and average velocity is zero.

• average velocity is zero , but not average soeed

A body covers a semi-circle of radius 7 cm in 5 seconds. Find its velocity.

• r / t = 7/5= 1.4 cm/s

• 2r / t=14 / 5=2.8 cm/s

Which of the following example shows an object does not change it magnitude of velocity but only its direction of motion?

• Parachutist bailing out of an aeroplane.

• Motion of a body along circular path.

• A body moving up against gravity.

• A car moving with uniform velocity in a straight line

Tags

NGSS.HS-PS2-2

Assertion : A Motion with uniform velocity is always along a straight line path.

Reason : In a uniform velocity motion, speed is the magnitude of the velocity and is equal to the instantaneous velocity.

• Both assertion and reason are true and reason is the correct explanation of assertion.

• Both assertion and reason are true but reason is not the correct explanation of assertion.

• Assertion is true but reason is false.

• Reason is true but assertion is false.