Force and Motion

A rocket is traveling toward space. What force must the rocket act against as it moves away from Earth?

• Inertia
• Gravity
• Magnetism
• Momentum

How does friction affect speed?

• More friction decreasesspeed
• More friction increases speed
• Less friction decreases speed

Machines are often full of moving parts that rub against each other .  In machines, a lubricant such as oil is often applied to these moving parts .  Why is this oil necessary?

• To enhance the effectiveness of friction
• To increase the efficiency of the machine
• To provide an additional source of energy
• To produce more thermal energy on the machine

Which of the following would increase the motion of a ball after it is kicked?

• A high, grassy surface
• A surface sloped uphill
• A surface sloped downhill

An airplane flies in a straight line between two cities that are separated by 840 kilometers. If it takes 4 hours for the airplane to make the trip, what is its average speed?

• 84 km/h
• 105 km/h
• 180 km/h
• 210 km/h

Melissa's dad drives north on the interstate going 70 miles per hour.  About hoe many miles will her dad travel in 2 hours?

• 70 miles
• 140 miles
• 180 miles

Anna ran 100 meters in 20 seconds.  What was her average speed?

• 2 m/s
• 5 m/s
• 20 m/s
• 25 m/s

How can the speed of an object best be determined?

• Distance traveled divided by time it took to travel
• Time it took to travel divided by distanced traveled
• Distance traveled divided by speed traveled
• Speed traveled by distance traveled

A group of 5th graders left school at 8:00 on a field trip to a museum 90 miles away. Which best describes the average speed of the bus if they got there at 10:00?

• 30 mph
• 35 mph
• 45 mph

Joey is studying motion. Which two measurements would Joey need to determine an object's speed?

• Distance and time
• Position and time
• Distance and direction
• Position and direction