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Gravity is pushing you down on the earth while the friction from the ground is pushing you up. Those are the two frictions you must overcome when walking.
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The work to stretch a spring from its rest position is
(1/2) (spring constant) (distance of the stretch)²
E = 1/2 k x² .
You said it takes 1700 joules to stretch the spring 3 meters from its rest position, so we can write
1700 joules = 1/2 k (3m)²
1 joule = 1 newton-meter
1700 N-m = 1/2 k (3m)²
Multiply each side by 2: 3400 N-m = k · 9m²
Divide each side by 9m² k = 3400 N-m / 9m²
= (377 and 7/9) newton per meter
Answer:
Velocity is a change in displacement over change in time and uses the units m/s.
Both are rates of change and can be positive or negative.
Acceleration is a change in velocity over change in time and uses the units m/s².
Explanation:
Velocity is the change in displacement over change in time, this makes it a rate of change. It can be positive or negative because it is a vector quantity. It uses the units m/s because that is a displacement unit over a time unit.
Acceleration is the change in velocity over change in time, this makes it a rate of change. It can be positive or negative because it is also a vector quantity. It uses the units m/s² (m/s/s) because that is a velocity unit over a time unit.
Answer:
1.5024
Explanation:
Draw a diagram. Put the two cells in series. Now draw 3 resistors. Two of them equal 0.26 ohms each. The third one is the lightbulb which is 12 ohms.
R = 0.26 + 0.26 + 12 = 12.52
The bulb has a voltage of 2.88 volts across it. You can get the current from that.
i = E / R
i = 2.88 / 12 =
i = 0.24 amps.
Now you can get the voltage drop across the two cells.
E = ?
R = 0.26
i = 0.24 amps
E = 0.26 * 0.24
E = 0. 0624
Finally divide the 2.88 by 2 to get 1.44
Each cell has an emf of 1.44 + 0.0624 = 1.5024
The power of the engine is 320 W.
<u>Explanation:</u>
Power may be defined as the rate of doing work (or) work done per unit time. One unit of energy is used to do the one unit of work.
Power = Work done / Time taken
Given, Force = 80 N, height = 5 m , final velocity = 4 m/s
To calculate the power, we must know the time taken.
To find the time, use the distance and speed formula which is given by
Time = Distance / speed
Here distance = 5 m and speed = 4 m/s
Time = 5 / 4 = 1.25 s.
Now, Power = work done / time
= (F * d) / t = (80 * 5) / 1.25
Power = 320 W.
The standard unit of power is watt (W) which is joule per second.
