Forces and Motion

The force of gravity is greater between two objects that

• have greater masses

• have rougher surfaces

• are moving at greater speeds

• are farther apart

You are on a bus moving north at 10 m/s and move from the front to the back of the bus at 2 m/s. Your resultant velocity is

• 8 m/s

• 8 m/s north

• 8 m/s south

• 12 m/s north

A bird flies 100 meters for 10 seconds and 300 meters for 10 seconds. What is the bird's average speed?

• 10 m/s

• 20 m/s

• 30 m/s

• 400 m/s

One of the largest forces opposing the motion of a car is

• fluid friction

• rolling friction

• sliding friction

• static friction

The SI unit for speed is

• m/h

• km/h

• mph

• m/s

The distance traveled divided by the time it took to travel that distance is the object's

• weight

• speed

• force

• acceleration

Brakes on a car use which type of friction?

• rolling

• static

• sliding

• fluid

The Law of Universal Gravitation describes the relationship between

• net force, unbalanced and balanced force

• force, mass and distance

• speed, distance and time

• speed, velocity and accelerationn

Which of the following will help reduce friction?

• Changing rolling to sliding friction

• Adding mass

• Lubricants

• Making the surface rougher

To calculate an object's acceleration, you need to know

• distance traveled and total time

• starting point, ending point and mass

• starting velocity, final velocity and time it takes to change velocity

• average speed and direction traveled