Answer:
The induced emf 1.43 s after the circuit is closed is 4.19 V
Explanation:
The current equation in LR circuit is :
.....(1)
Here I is current, V is source voltage, R is resistance, L is inductance and t is time.
The induced emf is determine by the equation :
Differentiating equation (1) with respect to time and put in above equation.
Substitute 6.05 volts for V, 0.655 Ω for R, 2.55 H for L and 1.43 s for t in the above equation.
D = vo t - at²/2
v = vo - at
40 m = vo · 7.10 - a · ( 7.10 )²/2
40 m = 7.10 vo - a· 50.41/2
40 m = 7.10 vo - 25.205 a
2.75 m/s = vo - 7.10 a ⇒ a = ( vo - 2.75 )/ 7.10
40 = 7.10 vo - 25.205 · ( vo - 2.75 ) / 7.10
40 = 7.1 vo - 3.55 vo + 9.7625
3.55 vo = 30.2375
vo = 30.2375 : 3.55 = 8.5176 m/s
Answer: the truck`s original speed is 8.5176 m/s.
Answer:
Balances and Scales
A balance compares an object with a known mass to the object in question. One example of a balance is the triple beam balance. The standard unit of measure for mass is based on the metric system and is typically denoted as kilograms or grams.
Answer:
Explanation:
Kinetic energy can be found using the following formula.
where <em>m</em> is the mass and <em>v</em> is the velocity.
The mass of the toy plane is 20 kilograms and the velocity is 10 meters per second.
Substitute the values into the formula.
Solve the exponent first.
- (10 m/s)²= 10 m/s *10 m/s= 100 m²/s²
Multiply the last two numbers together.
Multiply by 1/2 or divide by 2.
- 1 kilogram square meter per square second is equal to 1 Joule.
- Our answer of 1000 kg*m²/s² is equal to 1000 Joules
The kinetic energy of the toy plane is <u>1000 Joules</u>
