Data:
25 turn electromagnet
batter voltage: 1.5 V , 3.0 V , 4.5 V, 6.0V
paper clips picked up first try: 5, 12, 14, 20
paper clips picked up second try: 7, 12, 17, 26
average: 6, 12, 15.5, 23
50 turn electromagnet
battery voltage: 1.5 V, 3.0 V, 4.5 V, 6.0 V
paperclips picked up first try: 10, 28, 30, 44
paperclips picked up second try: 16, 24, 32, 50
average: 13, 26, 31, 47
Answer:
Option b. is true
Explanation:
- Light travel slower in glass than in air because of glass is denser than air and its refractive index is more than that of air. Therefore, except air, light travels slower in any other medium
Other options are not correct like
When an electromagnetic wave enters a new medium it speed as well as wavelength changes but frequency does not change.
Answer:
111 seconds
Explanation:
From research, it takes 4200 J to raise 1 kg of body temperature. Which means that specific heat capacity of human body with is; c = 4200 J/Kg°C
We are told that the temperature starts at 37°C and rises to 39.7°C
Thus: Δt = 39.7 - 37 = 2.7°C
Amount of energy required is given by the formula;
q = mcΔt
We are given m = 68 kg
Thus;
q = 68 × 4200 × 2.7
q = 77112 J
From research, the human body is 25% efficient.
Formula for power with velocity is;
P = F × V
F = mg = 68 × 9.81
V = 15km/h = 4.167 m/s
P = 68 × 9.81 × 4.167
P = 2779.72 W
Since the human body is 25%
Then the power of the utilized is;
25/100 × 2779.72 = 694.93 W
Now, we now that;
Power = work done/time taken
694.93 = 77112/t
t = 77112/694.93
t = 111 seconds.
Thus, it will take home 111 seconds to feel exhausted