Joe Burrow of the Cincinnati Bengals ate a turkey sandwich and an apple for lunch. Later that day, he spent 2 hours on the footb
all field warming up for the NFL playoffs. Which of the following energy transformations occured between lunchtime and the end of Burrow's workout routine?
A. Thermal energy was converted to kinetic energy.
B. Kinetic energy was converted to chemical energy.
C. Electrical energy was converted to thermal energy.
D. Chemical energy was converted to mechanical energy.
A. Thermal energy was converted to kinetic energy.
B. Kinetic energy was converted to chemical energy.
C. Electrical energy was converted to thermal energy.
D. Chemical energy was converted to mechanical energy.
1 answer:
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Answer:
This is about 176 times the weight of the froghopper.
Explanation:
the grasshopper converts kinetic energy into earth gravitational potential energy
u=mgh
u=12*10^-3*9.8*0.7
=8.23*10^-2
using the Work energy principle
equating the kinetic energy to the potential energy
k +U+w=K2+u2
K+0+0=0+U2
k=8.23*10^-2
force exerted by the grasshopper on the round will be given by tis equation
(F-mg)Ycos=k
(F-12*10^-3*9.8)*0.004cos 0=8.23*10^-2
F=20.7N
from newtons third law of motion, action and reaction are equal and opposite
F=-20.7N
comparing the forces by the two bodies
F:mg
-20.7:-12*10^-3*9.8
the magnitude of the force applied by the grasshopper is found to be 176 times the gravitational force
Answers:
a) 9.035 s
b) -88.543 m/s
Explanation:
The described situation is related to vertical motion (especifically free fall) and the equations that will be useful are:
(1)
(2)
Where:
is the final height of the steel ball
is the initial height of the steel ball
is the initial velocity of the steel ball (it was dropped)
is the final velocity of the steel ball
is the time it takes to the steel ball to reach the ground
is the acceleration due to gravity
<u>Knowing this, let's begin with the answers:</u>
<h2>a) Time it takes the steel ball to reach the ground</h2>We will use equation (1) with the conditions listed above:
(3)
Isolating :
(4)
(5)
(6)
We will use equation (2) with the conditions explained above and the calculaated time:
(7)
(8)
(9) The negative sign indicates the direction of the velocity is downwards