SPEED, VELOCITY & ACCELERATION

SPEED, VELOCITY & ACCELERATION

SPEED

• Speed is the measure how quickly distance changes with time.

• There are two types of speed: average speed and instantaneous speed.

• Average speed can be found by taking the total distance dividing by total time of travel

• Instantaneous speed is the speed of the object at the specific instant in time.

• Units for speed include mph with SI unit being m/s.

Multiple Choice

Find the speed of Sir Azwan’s car after 40 sec at 8 meters.

• 0.2 m/s

• 5 m/s

• 0.2 mph

• 40 mph

Using Equations to Solve for Speed, Distance, & Time

• Distance = speed x time

• Time = distance / speed

• Speed = distance / time

Multiple Choice

The average speed on 933 is 60mph and it is 30 miles from IISSA to Genting Highland. How long will it take to get to Genting Higland if I leave at 4pm?

• 5min

• 30 min

• 5hrs

• 30 sec

VELOCITY

• Velocity of an object is its speed combined with the direction of the motion

• Just add the direction to the speed and you have velocity

• An example of velocity would be 70m/s south

VECTOR vs SCALAR QUANTITY

• Velocity is a vector quantity while speed is a scalar quantity

• Vector quantity is a physical quantity that has both size and direction

• Scalar quantity is singular, size or direction.

Multiple Select

Check the correct examples of velocity

• 6km/h

• 4 km/h north

• 70mph

• 70mph east

• 25 feet up

ACCELERATION

• Acceleration is a measure how quickly velocity changes.

• Acceleration describes the change in velocity over time.

• The SI unit for acceleration is m/s^2

Multiple Choice

Shamel is running down the field at first going 15m/s then after 20 sec is going 30m/s. What is his acceleration?

• 0.75 mph

• 2m/s

• 0.75m/s² south

• 2mph

Multiple Select

How are speed and velocity different?

• Velocity has direction plus speed

• Speed is scalar while velocity is vector

• change in position

• one is normal and one is weird

Goes in opposite direction of velocity

• Can be negative (deacceleration)

• Goes in opposite direction of velocity

Multiple Choice

A train that travels 100 kilometers in 4 hours is traveling at what average speed?

• 50 km/h

• 100 km/h

• 2 km/h

• 25 km/h

Multiple Choice

If a bicyclist travels 30 km in 2 hours, her average speed is

• 30 km/h

• 60 km/h

• 15 km/h

• 2 km/h

Multiple Choice

Aina cycles at an average speed of 8km/h. How far has she traveled if she cycles for 4 hours?

• 55km

• 32km

• 43km

• 32miles

Multiple Choice

It took 3.5 hours for a train to travel the distance between two cities at a velocity of 120 km/hr. How many km lie between the two cities?

• 34 km

• 420 km

• 120 km

• 360 km

Multiple Choice

A car accelerates from a standstill to 70 m/s in 10 seconds. What is the acceleration?

• 0.7m/s

• 27m/s

• 214m/s²

• none of the above

Multiple Choice

A roller coasters accelerates from an initial velocity of of 6.0 m/s to a final velocity of 70 m/s over 4 seconds. What's the acceleration?

• 24 m/s²

• 18 m/s²

• 16 m/s²

• 16 m/s

Multiple Choice

A golf ball accelerates off a tee at 15m/s², changing its velocity from 0m/s to 50 m/s down the fairway. How long did it take the golf ball to accelerate?

• 750 s

• 35 s

• 0.3 s

• 3.3 s