How long will it take a 2190 W motor to lift a 1.47 x 104 g box, 6.34 x 104 mm vertically.
Answer:
4.2s
Explanation:
Given parameters:
Power = 2190W
Mass of box = 1.47 x 10⁴g
distance = 6.34 x 10⁴mm
Unknown:
Time = ?
Solution:
Power is the rate at which work is done;
Mathematically;
Power = [tex]\frac{work done}{time}[/tex]
Time = [tex]\frac{work done}{power}[/tex]
Work done = weight x height
convert mass to kg;
100g = 1kg;
1.47 x 10⁴g = 14.7kg
convert the height to m;
1000mm = 1m
6.34 x 10⁴mm gives 63.4m
Work done = 14.7 x 9.8 x 63.4 = 9133.4J
Time taken = [tex]\frac{9133.4}{2190}[/tex] = 4.2s
During the slowing down process, there is a time when the angular speed is 0.5 rev/s. The fan arm is 0.8 m long. What is the speed of a point on the end of the fan arm at this time
Answer:
2.51 m/s
Explanation:
Given that,
Angular speed of a fan, [tex]\omega=0.5\ rev/s = 3.14\ rad/s[/tex]
Length of the fan arm, r = 0.8 m
We need to find the speed of a point on the end of the fan arm at this time. Let v is the speed. It is given in terms of angular speed is given by :
[tex]v=r\omega\\\\v=0.8\times 3.14\\\\v=2.51\ m/s[/tex]
So, the required speed is 2.51 m/s.
Explain the procedures used and data recorded to identify a crystalline mineral based on its properties.
Answer:
By examining its external shape, color, hardness, etc.
Explanation:
A current of 15 Amps flows through a circuit with a resistance of 0.10 Ohms. What is the voltage?
A. 0.006 Volts
OB. 1.5 Volts
O C. 15 Volts
D. 150 Volts
Voltage = (current) x (resistance) (Ohm's law)
Voltage = (15 A) x (0.10 ohm)
Voltage = 1.5 volts (B)
which property of potential energy distinguishes it from kinetic energy
Answer:
Shape and position
Explanation:
Hope this helps! :)
Which statement correctly describes the diferences between positive and negative acceleration
O Positive acceleration describes a change in speed, negative acceleration desxibes no change in speed,
Positive acceleration describes no change in speed, negative acceleration desibes a change in speed,
Positive acceleration describes an increase in speed, negative sexeleration desnibes a decrease in speed
O Positive acceleration describes a decrease in speed, negative sideration describes an increase in sarees
Answer:The answer is this Positive acceleration describes an increase in speed, negative sexeleration desnibes a decrease in speed
Explanation:
1. A person weighs 155 lbs and is walking 3.1 miles per hour. How much kinetic energy does the person have? (Keep in mind, 1 kg is 2.2 lb, and 1 m/s is 2.24 mi/h.)2. What is the kinetic energy of a 5 g bullet travelling 400 m/s?
3. Is it possible to have a negative KE? Why or why not?
Answer:
Explanation:
Kinetic energy is expressed as;
KE =1/2 mv²
M is the mass
v is the velocity of the object
1) Given
Mass = 155lb
Velocity = 3.1mi/hr
Since 1kg = 2.2lb
x = 155lb
x= 155/2.2
x = 70.45kg
Also
1m/s = 2.24mi/hr
y = 3.1mi/hr
y = 3.1/2.24
y = 1.384m/s
KE = 1/2(70.45)(1.384)²
KE = 0.9577×70.45
KE = 67.47Joules
2) M = 5g =0.005kg
V = 400m/s
KE = 1/2(0.005)400²
KE = 80000×0.005
KE = 400Joules
3} Since a body decelerates (negative acceleration) this mean that the velocity of a body can be a negative value showing that it is possible for a moving body to possess negative kinetic energy.
A water molecule is made up of one oxygen and two hydrogen atoms. Why is water considered a pure substance?
Answer:
A mixture is when two or more substances combine physically together.
However, in water, two hydrogen atoms combine with one oxygen atom chemically, forming a new substance that has properties different from hydrogen alone or oxygen alone.
Explanation:
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Does electric and magnetic objects both have north and south poles
Explanation:
hope this answer was helpful
asheed and Sofia are riding a merry-go-round that is spinning steadily (uniform circular motion). Sofia is twice as far from the axis as is Rasheed. Sophia's acceleration is _________ that of Rasheed. *
Answer:
The same as
Explanation:
First of all, they are in a merry go round, which is a circular one. And thus, we would be dealing with circular motions.
The angular velocity of a merry go round, in this instance, is given by
w = Δ/Δt
The formula has nothing whatsoever to do with distance, and as such, both Rasheed and Sofia would have the same angular velocity.
Transferring this further, the angular acceleration is given as
α = Δw/Δt
Remember I said the velocity has nothing to do with distance, well, so does the acceleration as we can see from the formula stated. And therefore, both Rasheed and Sofia would have the same angular acceleration
When living things use chemical reactions to break down food, some of the energy is transformed into
OA. sound.
OB. heat.
OC. light
OD.waste
waste.
Answer:
OB. Heat
Explanation:
I hope this helped :)