A certain 100W light bulb has an efficiency of 95%. How much thermal energy will this light bulb add to the inside of a room in
1 answer:
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Recoil speed= 3m/s, method shown in photo
a) 2.64 s
We can solve this part of the problem by using the following SUVAT equation:
where
s is the displacement of the stone
u is the initial velocity
t is the time
a is the acceleration
We must be careful to the signs of s, u and a. Taking upward as positive direction, we have:
- s (displacement) negative, since it is downward: so s = -75.0 m
- u (initial velocity) positive, since it is upward: +15.5 m/s
- a (acceleration) negative, since it is downward: so a= g = -9.8 m/s^2 (acceleration of gravity)
Substituting into the equation,
Solving the equation, we have two solutions: t = -5.80 s and t = 2.84 s. Since the negative solution has no physical meaning, the stone reaches the bottom of the cliff 2.64 s later.
b) 10.4 m/s
The speed of the stone when it reaches the bottom of the cliff can be calculated by using the equation:
where again, we must be careful to the signs of the various quantities:
- u (initial velocity) positive, since it is upward: +15.5 m/s
- a (acceleration) negative, since it is downward: so a = g = -9.8 m/s^2
Substituting t = 2.64 s, we find the final velocity of the stone:
where the negative sign means that the velocity is downward: so the speed is 10.4 m/s.
c) 4.11 s
In this case, we can use again the equation:
where
s is the displacement of the package
u is the initial velocity
t is the time
a is the acceleration
We have:
s = -105 m (vertical displacement of the package, downward so negative)
u = +5.40 m/s (initial velocity of the package, which is the same as the helicopter, upward so positive)
a = g = -9.8 m/s^2
Substituting into the equation,
Which gives two solutions: t = -5.21 s and t = 4.11 s. Again, we discard the first solution since it is negative, so the package reaches the ground after
t = 4.11 seconds.
Answer:
a. 1. she informed the audience when she was concluding
2. She simply outlined the steps tying her conclusion to the topic
3. her conclusion was concise and simple.
b. 13.1 grams
Explanation:
a. signalling the end of a speech prepares the mind of the audience and leaves them satisfied, and Kara correctly signaled the end of her speech when she said "In conclusion".
Also, Kara summarized the ideas in her speech by simply outlining the requirements needed to get a U.S passport.
Her conclusion was concise and simple which is very important especially for lengthy speeches because the audience at this point must be getting tired and distracted.
b. Amount of cholesterol in 100 mL of blood = 248 mg
Total Volume of blood = 5.3 Liters.
the question is asking us to find the total grams of cholesterol in the individual's body, that is the total grams of cholesterol in 5.3 Liters of the individuals blood.
To solve, let us use the following steps:
1. unify the units of measuring volume.
since the first volume is given in Milliliters, I will convert the second volume (5.3 Liters) to milliliters too. To do this, note that:
1 liter = 1000 Milliliter (mL)
∴ 5.3 Liters = 5.3 × 1000 = 5300 Milliliters (mL)
2. Calculate the amount of cholesterol in 5300 mL.
100 mL = 248 mg of cholesterol
∴ 1 mL = = 2.48 mg
∴ 5300 mL = 2.48 × 5300 = 13,144 mg of cholesterol.
3. Convert the amount of cholesterol from Milligram to gram
Since the question asked for the gram of cholesterol, not the milligram of cholesterol, converting from milligram to gram, we use the following steps:
1000 mg = 1 g
∴ 1 mg = g
∴ 13144 mg = 13144 × =
= 13.144 ≅ 13.1 g of cholesterol ( 1 decimal place).
I suggest you go and study the conversion relationships between the sub units milli, micro, centi and deci.
Answer:
the velocity at point B is 27120.08 km/hr
Explanation:
check the picture attached for explanation
