Answer:
1.59 seconds
12.3 meters
but if you are wise you will read the entire answer.
Explanation:
This is a good question -- if not a bit unusual. You should try and understand the details. It will come in handy.
Time
<u>Given</u>
a = 0 This is the critical point. There is no horizontal acceleration.
d = 20 m
v = 12.6 m/s
<u>Formula</u>
d = vi * t + 1/2at^2
<u>Solution</u>
Since the acceleration is 0, the formula reduces to
d = vi * t
20 = 12.6 * t
t = 20 / 12.6
t = 1.59 seconds.
It takes 1.59 seconds to hit the ground
Height of the building
<u>Givens</u>
t = 1.59 sec
vi = 0 Another critical point. The beginning speed vertically is 0
a = 9.8 m/s^2 The acceleration is vertical.
<u>Formula</u>
d = vi*t + 1/2 a t^2
<u>Solution</u>
d = 1/2 a*t^2
d = 1/2 * 9.8 * 1.59^2
d = 12.3 meters.
The two vi's are not to be confused. The horizontal vi is a number other other 0 (in this case 12.6 m/s horizontally)
The other vi is a vertical speed. It is 0.
I think it is c I'm only in 7th grade but I'm pretty sure that the answer is c
Answer: 55 ohms
Explanation:
Given that,
Voltage of heater (v) = 110-volt
Current drawn by heater (I) = 2.0 amperes
resistance of the heater (r) = ?
Since voltage, current and resistance are involved, apply the formula for ohms law.
Voltage = current x resistance
i.e v = ir
where r = v / i
r = 110 volts / 2.0 A
r = 55 ohms
Thus, the resistance of the heater is 55 ohms
Answer:
1) energy = 15.6 kWh, 2) total_cost = $ 2.03
Explanation:
1) The energy dissipated is the product of the power and the time of use In a month it was used t = 6.5 h and the power of the toaster is
P = 2400 W = 2,400 kW
energy = P t
energy = 2,400 6.5
energy = 15.6 kWh
using rounding to a decimal
energy = 15.6 kWh
2) The cost of energy is unit_cost = $ 0.13 / kWh
so the total cost
total_cost = energy unit_cost
total_cost = 15.6 0.13
total_cost = $ 2.028
rounding to two decimal places
total_cost = $ 2.03