Answer: The truck's velocity after braking = 17m/s.
Explanation:
Given: Initial velocity(i) = 25 m/s
Time(t) = 4s
Acceleration(a) = -2 m/s ²
We use the following formula to compute final velocity (v):
![v= i+at\\\\\Rightarrow\ v=25+(-2)(4\ \ \ [\text{Substitute all values}]\\\\\Rightarrow\ v=25-8\\\\\Rightarrow\ v=17\ m/s](https://tex.z-dn.net/?f=v%3D%20i%2Bat%5C%5C%5C%5C%5CRightarrow%5C%20v%3D25%2B%28-2%29%284%5C%20%5C%20%5C%20%5B%5Ctext%7BSubstitute%20all%20values%7D%5D%5C%5C%5C%5C%5CRightarrow%5C%20v%3D25-8%5C%5C%5C%5C%5CRightarrow%5C%20v%3D17%5C%20m%2Fs)
Hence, the truck's velocity after braking = 17m/s.
The answer is B increase the resistance of the circuit
Answer:
The thermal efficiency is 43%.
The total amount of energy developed by work is 397 kW in one year.
Explanation:
Given that,
Power output = 0.3 kW
Heat energy = 2400 Btu/h = 0.703 kW
We need to calculate the thermal efficiency
Using formula of efficiency
Put the value into the formula
The thermal efficiency is 43%.
(b). We need to calculate the total amount of energy
Using formula of energy
Hence, The thermal efficiency is 43%.
The total amount of energy developed by work is 397 kW in one year.
A campfire being lighted and plants converting carbon-dioxide and water into glucose and oxygen are both forms of chemical change.
Therefore, the answer is:
B. Both are examples of chemical change.
Given
m1(mass of the first object): 55 Kg
m2 (mass of the second object): 55 Kg
v1 (velocity of the first object): 4.5 m/s
v2 (velocity of the second object): ?
m3(mass of the object dropped): 2.5 Kg
The law of conservation of momentum states that when two bodies collide with each other, the momentum of the two bodies before the collision is equal to the momentum after the collision. This can be mathemetaically represented as below:
Pa= Pb
Where Pa is the momentum before collision and Pb is the momentum after collision.
Now applying this law for the above problem we get
Momentum before collision= momentum after collision.
Momentum before collision = (m1+m2) x v1 =(55+5)x 4.5 = 270 Kgm/s
Momentum after collision = (m1+m2+m3) x v2 =(55+5+2.5) x v2
Now we know that Momentum before collision= momentum after collision.
Hence we get
270 = 62.5 v2
v2 = 4.32 m/s
