1. Mary has a mass of 40 kg and sprints at 1 m/s. How much kinetic energy does she have?

2. Roberto has twice the mass his sister Mary has (see above) but runs at the same velocity as Mary. Will his kinetic energy be twice as much? Show your work.

What happens to Roberto’s kinetic energy when he runs twice as fast?

3. Use the kinetic energy formula KE = 0.5 mv2 to complete the practice problems below. Remember, 1 J = 1 kg ∙ m2 /s2 . Also, velocity is v 2 = KE / (0.5 x m), and mass is m = KE / (0.5 v2 ).

4. What is the kinetic energy of a 150 kg object that is moving at a speed of 15 m/s?

5. An object has a kinetic energy of 500 J and a mass of 30 kg. How fast is the object moving?

6. An object moving with a speed of 5 m/s has a kinetic energy of 100 J. What is the mass of the object?

7. What is the kinetic energy of a 1,200 kg object that is moving at a speed of 24 m/s?

Please help ASAP :(

1. Mary has 20 joules of Kinetic energy

2. Yes his kinetic energy be twice as much

3. If Roberto runs twice as fast, his Kinetic energy will be 4 times as much

4. 16875 Joules

5. 5.77 m/s

6. 8 kg

7. 345600 J

Explanation:

The formula for Kinetic Energy is given as

We will apply this in solving all the problems below using the parameters provided by each problem.

1. Mary's Kinetic Energy will be equal to

2a. If Roberto has twice Mary's mass, his mass will be 80 kg.

His K.E will be

2b. If Roberto runs twice as fast, his kinetic energy will be . This is four times its initial value

4.

5.

6.

7.

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."

measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.