Kinematics Equations Practice

A quantity that is has magnitude and  direction is referred to as a

• vector quantity
• scalar quantity

Tags

NGSS.MS-PS2-5

An object can be moving for 10 seconds and still have zero displacement.

• True
• False

You run from your house to a friend's house that is 3 km away. You then walk home. The distance you traveled is 6 km. What is your displacement? 

• 6  km
• 0 km

A hummingbird averages a speed of about 45 km/hour (Cool facts: They visit up to 1000 flowers per day, and reach maximum speed, while diving, up to 160 km/hour!). Ruby-throated hummingbirds take a non-stop trip across Gulf of Mexico in which they fly for 18 hours straight! How far is the trip across the Gulf of Mexico at their average speed?

• 810 km
• 2.5 km
• 3.6 km
• 360 km

A car accelerates uniformly from rest at 3.2m/s ² when the car traveled a distance of 40 m it’s speed will be

• 12.5 m/s

• 8.0m/s

• 16m/s

• 128m/s

A car is traveling south for 250 meters over the course of 100 seconds. What was the car's average velocity?

• 0.4 m/s south

• 0.4 m/s

• 2.5 m/s

• 2.5 m/s south

A car is travelling along the road. It starts at 10 m/s and accelerates to a velocity of 25 m/s. It speeds up over a period of 5 seconds. What is the acceleration?

Answer explanation

Our knowns are:

Vi = 10m/s; Vf = 25m/s; t = 5s

We are looking for acceleration (a)

Our formula is:

Vf = Vi + at

25m/s = 10m/s + a(5s)

-10m/s -10m/s

15 = a(5s)

divide both sides by 5s

t = 3m/s^2

Tags

NGSS.HS-PS2-1

A car is travelling along the road. It starts at 10 m/s and accelerates to a velocity of 25 m/s. It speeds up over a period of 5 seconds. What distance does it travel during this time?

• 62.5 m

• 77.5 m

• 82.5 m

• 87.5 m

Answer explanation

Our knowns are

Vi =10 m/s; Vf = 25 m/s; t = 5s

We are looking for distance. In order to find distance, we can first find acceleration.

Our formula is:

a = change in velocity/t

a = (25 m/s - 10 m/s)/5s

a = (15)/5

a = 3 m/s^2

Now distance:

d = vit + 1/2at^2

d = (10m/s)(5s) + (1/2)(3m/s^2)(5s)^2

d = 50 + 37.5

d = 87.5m

Tags

NGSS.HS-PS2-1

A bicyclist is travelling along a bike path in the park at a constant velocity of 4 m/s. A deer darts in front of the bicyclist and they hit the brakes. The brakes decelerate the bike at -2 m/s^2.

How long does it take the bicyclist to stop?

• 0.5s

• 1.0s

• 1.5s

• 2.0s

Answer explanation

Our knowns are:

Vi = 4 m/s, Vf = 0 m/s,

a = -2m/s^2

We are looking for time t

Our equation is

Vf = Vi + at

0 m/s = 4 m/s + -2m/s^2 (t)

add + 2 m/s^2 (t) to both sides

2 m/s^2(t) = 4 m/s

Divide both sides by 2 m/s^2

t = 2s

Tags

NGSS.HS-PS2-1

A bicyclist is travelling along a bike path in the park at a constant velocity of 4 m/s. A deer darts in front of the bicyclist and they hit the brakes. The brakes decelerate the bike at -2 m/s^2.

What is the distance it takes the until the bicyclist stops?

• 1.5m

• 2.25m

• 4.0m

• 8.0m

Answer explanation

Our knowns are:

Vi = 4 m/s, Vf = 0 m/s,

a = -2m/s^2

We are looking for distance

Our equation is

Vf^2 = Vi^2 + 2ad

(0 m/s)^2 = (4 m/s)^2 + 2(-2m/s^2)d

0 = 16 + -4d

-16 = -4 d

d = 4 m

Tags

NGSS.HS-PS2-1