Answer:
A. 231.77 J
B. 5330.71 J
C. 46 donuts
Explanation:
A. To lift the barbell once, she will have to extend it the full length of her arm. The work done will then be:
W = F * d
Where the force is the weight of the barbell.
F = m * g
Hence, the work done in lifting the barbell is:
W = m * g * d
W = 43 * 9.8 * 0.55
W = 231.77 J
B. If she does 23 repetitions, the total energy she expend will be equal to the Potential energy when the barbell is lifted multiplied by 23:
E = 23 * m * g * d
E = 23 * 231.77
E = 5330.71 J
C. 1 Joule = 4.184 calories
5330.71 Joules = 5330.71 * 4.184 = 22303.69
If 1 donut contains 490 calories, the number of donuts she will need will be:
N = 22303.69/490 = 45.5 donuts or 46 donuts
Answer:
(C) deflected toward the top of the page.(
Explanation:
We can answer this problem by using Fleming's Left Hand Rule. By doing so, we have to place:
- The index finger of the left hand in the direction of the magnetic field
- The middle finger of the left hand in the direction of the particle's velocity
- The thumb will give the direction of the force, and therefore the deflection of the proton
In this problem, we have:
- Magnetic field direction: into the page --> index finger
- Proton's velocity: to the right --> middle finger
By doing so, we observe that the thumb points towards the top of the page: therefore, the correct answer is
(C) deflected toward the top of the page.
