Its Time Its Time To Practice Your Formulas

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It’s Time, It’s Time To Practice Your Formulas!

It’s Time, It’s Time To Practice Your Formulas!

Question 1 • A car stopped at a red light. When the light turned

Question 1 • A car stopped at a red light. When the light turned green it accelerated to 30 m/s in 15 s. What was its acceleration? Just a hint to everyone: Don’t forget your 4 Steps to answer! Mr. Alarm Clock

And the answer is… A = Vf – V i t A = 30

And the answer is… A = Vf – V i t A = 30 m/s – 0 m/s 15 sec A = 2 m/s/s

Question 2 You took a car trip with your family to visit Thomas Jefferson’s

Question 2 You took a car trip with your family to visit Thomas Jefferson’s home which was 750 km away. The trip took 8 hours. What was your average speed in km/hr?

And the answer is… V= d t V = 750 km 8 hr V

And the answer is… V= d t V = 750 km 8 hr V = 93. 75 km/hr

Question 3 If you travel 50 km due east in 2 hours, what is

Question 3 If you travel 50 km due east in 2 hours, what is your velocity?

and the answer is… V= d t V = 50 km 2 hr V

and the answer is… V= d t V = 50 km 2 hr V = 25 km/hr East

Question 4 A train takes 10 minutes to slow down to 10 m/s from

Question 4 A train takes 10 minutes to slow down to 10 m/s from 40 m/s. What is its acceleration?

and the answer is… A = Vf – V i t A = 10

and the answer is… A = Vf – V i t A = 10 m/s – 40 m/s 10 min A = -3 m/s/min

Question 5 The traffic on the highway you are traveling moves at 90 km/

Question 5 The traffic on the highway you are traveling moves at 90 km/ hr. At this rate, how long will it take you to travel 450 km?

and the answer is… V = D/T T=D V T= 450 km 90 km/hr

and the answer is… V = D/T T=D V T= 450 km 90 km/hr T = 5 hours

Question 6 You pedal your 20 kg bicycle at 3 m/s. What is the

Question 6 You pedal your 20 kg bicycle at 3 m/s. What is the kinetic energy of your bicycle?

and the answer is… KE = ½ m v 2 KE = ½ (20

and the answer is… KE = ½ m v 2 KE = ½ (20 kg)(3 m/s)2 KE = 90 Joules

Question 7 A baseball is thrown at a velocity of 40 m/s and has

Question 7 A baseball is thrown at a velocity of 40 m/s and has a mass of 0. 2 kg. What is its kinetic energy?

and the answer is… KE = ½ m v 2 KE = ½ (0.

and the answer is… KE = ½ m v 2 KE = ½ (0. 2 kg)(40 m/s)2 KE = 160 Joules

Question 8 What is the gravitational potential energy of a 60 kg skier at

Question 8 What is the gravitational potential energy of a 60 kg skier at the top of a hill that is 20 m high?

and the answer is… GPE = mgh GPE = (60 kg)(9. 8 m/s/s)(20 m)

and the answer is… GPE = mgh GPE = (60 kg)(9. 8 m/s/s)(20 m) GPE = 11, 760 Joules

Question 9 Suppose you took a rock with a mass of 63 kg to

Question 9 Suppose you took a rock with a mass of 63 kg to the moon where the gravitational force is 1/6 that of the earth. What would the rock weigh on the moon?

and the answer is… Moon Ag vs Earth Ag: 9. 8 m/s/s x 1/6

and the answer is… Moon Ag vs Earth Ag: 9. 8 m/s/s x 1/6 (9. 8 m/s/s ÷ 6) Moon Ag = 1. 6 m/s/s W = mg W = (63 kg) (1. 6 m/s/s) W = 101 Newtons

Question 10 An arrow leaves a bow with a force of 500 N. The

Question 10 An arrow leaves a bow with a force of 500 N. The mass of the arrow is 250 g. What is the acceleration of the arrow? (Remember to make your conversion…)

and the answer is… F = ma A=F m A = 500 N 0.

and the answer is… F = ma A=F m A = 500 N 0. 25 kg A = 2000 m/s/s

Question 11 A student’s full backpack weighs 10 N. She lifts it from the

Question 11 A student’s full backpack weighs 10 N. She lifts it from the floor to a shelf 1. 5 m high. How much work is done on the pack full of books?

and the answer is… W = fd W = (10 N)(1. 5 m) W

and the answer is… W = fd W = (10 N)(1. 5 m) W = 15 Nm or 15 Joules

Question 12 Work is measured in Newton-meters, also known as _____.

Question 12 Work is measured in Newton-meters, also known as _____.

and the answer is… Joules

and the answer is… Joules

Question 13 _____ is energy in the form of motion.

Question 13 _____ is energy in the form of motion.

and the answer is… Kinetic Energy

and the answer is… Kinetic Energy

Question 14 _____ is the ability to cause change, or do work.

Question 14 _____ is the ability to cause change, or do work.

and the answer is… Energy

and the answer is… Energy

and the answer is… Energy

and the answer is… Energy

Question 15 Energy, like work, is measured in _____.

Question 15 Energy, like work, is measured in _____.

and the answer is… Joules

and the answer is… Joules

Question 16 Energy that is stored in an object or a system is _____.

Question 16 Energy that is stored in an object or a system is _____.

and the answer is… Potential Energy

and the answer is… Potential Energy

Question 17 The Law of Conservation of Mass and Energy states…

Question 17 The Law of Conservation of Mass and Energy states…

and the answer is… matter and energy can not be created or destroyed, they

and the answer is… matter and energy can not be created or destroyed, they can only be rearranged/ transformed from one type to another… The amount present in the universe is always constant.

Question 18 The pulling force of gravity on Earth is _____.

Question 18 The pulling force of gravity on Earth is _____.

and the answer is… 9. 8 m/s/s

and the answer is… 9. 8 m/s/s

Question 19 If Maria uses 4 N of force to lift a box onto

Question 19 If Maria uses 4 N of force to lift a box onto a shelf 0. 5 m high, how much work did she do?

and the answer is… W = FD W = (4 N)(0. 5 m) W

and the answer is… W = FD W = (4 N)(0. 5 m) W = 2 Nm or 2 Joules

Question 20 Rita mows lawns on the weekend. If she uses 15 N of

Question 20 Rita mows lawns on the weekend. If she uses 15 N of force to move a lawn mower a distance of 10 meters, how much work does Rita do?

and the answer is… W = FD W = (15 N)(10 m) W =

and the answer is… W = FD W = (15 N)(10 m) W = 150 Joules

Bonus… Albert Einstein’s equation E = mc 2 represents why nuclear reactions release so

Bonus… Albert Einstein’s equation E = mc 2 represents why nuclear reactions release so much more energy in their transformations than other types of stored energy. The ‘c’ stands for the speed of light: 300, 000 m/s. Can you explain why transforming energy from the matter of a nucleus releases so much more? Since the speed of light is such a large number and the equation squares it, any amount of matter multiplied by this constant is going to result in an incredibly large release of energy- mostly thermal in type…

The End

The End