Newton’s First Law of Motion - Questions

Question

1. Indicate which statement is true(T) or false(F)? If false then change the word or phrase that is bold and underlined to make it true.

____ The reason your head feels like it jerks backward when pulling away from a stop sign is best explained by Newton’s First Law.

_____ An airplane is flying in level flight with constant velocity. The forward “thrust” force acting on the airplane is greater than the “drag” force acting in the opposite direction.

_____ If two forces that are identical in strength but exactly opposite in direction act on the same object, that

object must be motionless.

_____ If the vector sum of all forces acting on an object is precisely zero, the object could still be moving.

_____ An elevator moves vertically upward with a constant speed. The vector sum of all the forces acting on the elevator is precisely zero.

2. Describe the outside unbalanced external force that would change the state of rest for the following object

a) An ice cube sits in a glass, or on a counter, or in an ice cube tray on a table.

b) A tennis ball is let go from a height and for a split second is stationary.

c) Your head is stationary in a car and the car moves forward suddenly. Think about this carefully

3. Describe the outside unbalanced external force that would change the state of constant speed for the following object.

a) A skydiver is falling with terminal speed when the parachute is released.

b) A student on their bike travelling with a constant speed along a horizontal road takes their foot off the pedal.

c) You are in the passenger seat, buckled in, of a car moving with constant speed and the brakes are suddenly applied.

Answer 1

1/ True

False Equal to

False may [ be motionless]

True

True

2/ I do not understand the question

3/ I do not understand the question