Physics: Vectors, Motion, and Forces Key Concepts

Which of the following quantities is a vector?

velocity

What is the main difference between scalars and vectors?

vectors have direction scalars dont

If a car travels 400 km east and then 600 km west, what is the displacement?

200 km west

A person walks from a Cinema to a Post Office 20 east, then to a Bakery 40m west. What is the total distance they travelled?

60 m

Which concept relates to a change in position?

displacement

If a car travels in a circle back to its starting point, what is its displacement?

zero

Which is an example of a scalar quantity with a unit?

20 kg

Which physical quantity is obtained by dividing change in velocity by time?

acceleration

A car accelerates uniformly from 10 m/s to 50 m/s over 20 seconds. What is its acceleration?

2 m/s squared

Using the first equation of motion (v2 = v1 + at), calculate the final velocity of an object that starts at 1 m/s and accelerates at 1 m/s² for 1 seconds.

2 m/s

An object is thrown upward with an initial speed of 10 m/s on Earth. Using the equation of motion v22=v12+2a(x2-x1), how high will it go? Assume acceleration due to gravity is -10 m/s².

5 m

If an object starts from rest and ends at rest, what do we know?

only a and b : initial final velocity is 0 and final velocity is 0

Solve for time in the equation of motion: d = v1t + 1/2at², when d = 500 m, v1 = 0, and a = 10 m/s².

10s

How many significant figures are there in the number 0.00450?

3

What is the number of significant figures in the number 0.05270?

4

What is the SI unit for measuring velocity?

m/s

A car accelerates at a rate of 5 m/s2 for 20 s over a distance of 100 m. What does the number 100 represent in this problem?

delta D

Which of the following quantities go to zero at the maximum height a baseball will reach after being tossed straight up?

vertical velocity

The slope of a velocity-time graph gives what information?

average acceleration

The slope of a position-time graph gives what information?

average velocity

When adding vectors, what is the starting point of the resultant vector?

the tail of the first vector

Which angle measurement indicates a vector pointing directly Northeast?

45 degrees

What does the tail of a vector represent in vector drawing and addition?

the starting point of the vector

Which of the following best describes a vector?

a quantity that has both magnitude and direction

Which of the following scenarios best illustrates projectile motion?

a football kicked in a parabolic path

What is the primary reason a horizontally launched projectile eventually hits the ground?

gravity

How can two objects dropped from the same height and time land on the ground at the same time?

lack of air resistance

Which term describes the curve traced by a projectile launched at an angle?

parabolic path

If two identical objects fall from a height, one is dropped and the other is pushed horizontally, which hits first?

both at the same time due to gravity

What happens to the horizontal velocity of a projectile when air resistance is ignored?

it remains constant

Which factor does not affect the time an object remains in projectile motion?

objects mass

How does increasing launch speed impact the range of a projectile?

increases the range

You are swimming upstream at a rate of 2 m/s. If the current is 1/ms downstream, what is your overall velocity with respect to the bank of the river?

1 m/s upstream

You want to swim to a spot directly across the river bank (due east). If there is a current headed south, how must you direct your motion to land in the intended location?

north and east

What value goes to zero at max height?

vertical velocity

A woman walks 10 m NE then 20 m SW. What is her final displacement?

10 m SW

You walk 3 m due east and 4 m due north. What is the magnitude of your displacement?

5 m

You walk 3 m due east and 4 m due north. What is the total distance traveled?

7 m

You launch a cannonball toward a ship. What is true about the object's initial velocity?

it determines whether or not the cannonball will reach the ship

The sum of two vectors is zero. Which of the following statements is true?

the vectors point in opposite directions and have the same length

Which philosopher's views on motion suggested that heavier objects fall faster due to their desire to reach the Earth's center?

aristotle

What did Galileo demonstrate when he dropped two objects of different masses but the same shape?

objects fall at the same rate regardless of mass

According to Newton's First Law, what happens to an object in space if no external forces act upon it?

it wil maintain its state of motion or rest

What happens to the acceleration of an object when the net force on it is doubled, assuming mass remains constant?

the acceleration doubles

A 10 kg object experiences a net force of 30 N. What is the acceleration of the object?

3 m/s squared

When a hockey player checks another player with a force, what force does the second player exert back?

equal magnitude, opposite direction

If you push against a wall with a force of 25 N, what is the force exerted by the wall on you?

25 N, opposite direction

Why do you feel a sting when you slap a table hard?

Because the table exerts an equal and opposite force on your hand

Which force is responsible for holding the nuclei of atoms together?

Strong nuclear force

Which of the following is not a characteristic of gravitational force?

repulsive

If the distance between two objects is doubled, what happens to the gravitational force between them according to the Universal Law of Gravity?

The force is reduced to one-fourth

How does the normal force change when additional force is applied to an object on a surface?

It increases to balance the additional force.

What happens to the reading on a bathroom scale if the elevator is accelerating upwards?

It increases because the normal force is greater than the gravitational force.

What force prevents an apple from slipping off a slanted surface if it is not accelerating?

static friction

Which scenario is an example of kinetic friction?

a sled sliding on the snow

What does Hooke's Law state about the relationship between force and the deformation of a spring?

The force required to extend or compress a spring is directly proportional to the extension or compression of the spring.

If a spring with a spring constant of 400 N/m is stretched by 1.5 meters, what is the force applied to the spring?

600 N

A bungee jumper uses a cord which stretches from 15 m to 55 m. What is the extension of the bungee cord?

40 M

What is the primary determination factor for the acceleration direction of a system of objects?

the net force acting on the system

When objects in a system are not in equilibrium, what is the consequence?

The objects accelerate in the direction of the net force.

In physics, which of the following quantities does momentum depend on?

both mass and velocity

Which of the following best describes the direction of an object's momentum?

Same as the direction of the object's velocity

What happens to the momentum of an object if its velocity doubles?

the momentum doubles

What is the main concept behind impulse in physics?

impulse is the product of force and time

If a force is applied over a longer period of time, how does it affect impulse?

Increases the impulse

Why does cradling a water balloon when catching prevent it from popping?

It increases the time over which momentum changes, reducing force applied on the balloon.

What is the main factor determining if a collision between two carts on a near-frictionless track is isolated?

Absence of external forces

In an elastic collision, which of the following is ALWAYS true?

Both kinetic energy and momentum are conserved

In a figure skating pair, when one skater throws another, how does it affect the velocities of both skaters based on conservation of momentum?

The first skater slows down as the other speeds up

What is a significant characteristic of inelastic collisions compared to elastic collisions as per the content?

Energy is not conserved in inelastic collisions.

In the context of special cases of elastic collisions in 1-D, what occurs when a second mass is very large compared to the first mass?

The first mass rebounds with a velocity equal to its initial.

When two identical masses undergo an elastic collision and one is stationary, which equation describes the conservation of momentum?

v1 initial = v2 final

If a second mass is initially stationary in an elastic collision, which direction will both objects' final velocities most likely follow?

Same direction as the first mass' initial velocity.

In a 1-D elastic collision, if two masses m1 and m2 are identical, what is a likely result in terms of their velocities?

The two masses exchange velocities.

In a 2-dimensional collision where one object splits into two pieces of equal mass, what can be said about the velocities of the two pieces immediately after the explosion?

The velocities are equal in magnitude and opposite in direction.

How does the law of conservation of momentum apply in a situation where a stationary firework explodes into multiple pieces?

The total momentum before and after the explosion is the same.

Which type of collision involves two vehicles traveling in opposite directions colliding?

head-on collision

In a rear-end collision scenario described, which vehicle is typically faster?

The vehicle striking from behind

Why is follow-through important in sports like tennis and golf?

It allows force to be applied over a longer time, increasing momentum.

What defines an 'explosion' in terms of physics concepts?

An object or group of objects breaking into multiple parts.