If a book has a a mass of 2 kg, how much does the book weigh?
1 answer:
You might be interested in
Answer:
P = 2439.5 W = 2.439 KW
Explanation:
First, we will find the mass of the water:
Mass = (Density)(Volume)
Mass = m = (1 kg/L)(10 L)
m = 10 kg
Now, we will find the energy required to heat the water between given temperature limits:
E = mCΔT
where,
E = energy = ?
C = specific heat capacity of water = 4182 J/kg.°C
ΔT = change in temperature = 95°C - 25°C = 70°C
Therefore,
E = (10 kg)(4182 J/kg.°C)(70°C)
E = 2.927 x 10⁶ J
Now, the power required will be:
where,
t = time = (20 min)(60 s/1 min) = 1200 s
Therefore,
<u>P = 2439.5 W = 2.439 KW</u>
Answer:
maximumforce is F = mg
Explanation:
For this case we must use Newton's second law,
Σ F = m a
bold indicate vectors, so we will write it in its components x and y
X axis
Fₓ = maₓ
Axis y
Fy - W = m a
Now let's examine our case, with indicate that the bird is level, the force of the wings can have a measured angle with respect to the x axis, where the vertical component is responsible for the lift, let's use trigonometry to find the components
Cos θ = Fₓ / F
Fₓ = F cos θ
sin θ = Fy / F
Fy = F sin θ
Let's replace and calculate
F sin θ -w = m a
As the bird indicates that leveling at the same height, so the vertical acceleration is zero (ay = 0)
F sin θ = w = mg
The maximum value of this equation occurs when the sin=1, in this case
F = mg
a) 4.8 m/s² his average acceleration during the first 2.5 s
b) 15 m distance he cover during the first 2.5 seconds.
c) 31 m/s his speed as he finished the race.
<h3>(a) How to calculate the Average Acceleration ?</h3>Average acceleration is calculated by using Newtons first law of motion
v = u + at
where
u is initial velocity
v is final velocity
a is constant acceleration
t is time
Given u = 0m/s , v = 12 m/s and t = 2.5 sec
Therefore average acceleration is given by
a = 4.8 m/sec²
b) Here we will use newtons second law of motion
On substituting value we get
s = 15m
c) Here we will use newtons third law of motion
v² = u² + 2as
Here u = 0 , a = 4.8 m/s² and s = 100 m
Therefore
v² = 960
v = 31 m/s
Disclaimer: the question was given incomplete in the portal. Here is the complete question.
Question: Usain Bolt's 100m sprint Runner set the world record for the100 meter sprint during the 2009World Championships in Berlin with a time of 9.58 s, reaching a top speed of 12 m/s in about 2.5 s.
a. What was his average acceleration during the first 2.5 s?
b. What distance did he cover during the first 2.5 seconds, assuming his acceleration was constant?
c. If he were able to maintain this constant rate of acceleration, what would have been his speed as he finished the race?
Learn more about Newtons law of motion here:
#SPJ4