Answer:
1.) h = 164.8 m
2.) U = 49.1 m/s
3.) t = 1.43 seconds
Explanation:
1.) A soccer ball is dropped from the top of a building. It takes 5.8 seconds to fall to the ground. The height of the building is...?
Since the soccer ball is dropped from the building, the initial velocity U will be equal to zero
Using second equation of motion
h = Ut + 1/2gt^2
Substitutes the time into the formula
h = 1/2 × 9.8 × 5.8^2
h = 164.8 m
2. The Falcon 9 launches to a height of 123 meters. What is its vertical initial velocity?
At maximum height final velocity = 0
Using the third law of motion
V^2 = U^2 - 2gH
0 = U^2 - 2 × 9.8 × 123
U^2 = 2410.8
U = 49.1 m/s
3. An apple falls from rest off a 10.m m tree. How long will it take before it hits the ground?
Since the apple fall from rest, the initial velocity U will be equal to zero
Using the second equation of motion,
h = Ut + 1/2gt^2
substitute all the parameters into the formula
10 = 1/2 × 9.8 × t^2
10 = 4.9t^2
t^2 = 10/4.9
t^2 = 2.04
t = 1.43 seconds
Answer:
a) current in the second wire is 5.60A
b) opposite directions
Explanation:
a) We need to find the current of wire, the magnitude of the force per unit length between the two wires carrying current I and I¹ is given by
b) knowing that for a two parallel conductor carrying current in the same direction attracts each other, and for a two parallel conductors carrying carying current in opposite direction repels eachother.
therefore, since the two wire repel each other then the current in the second wire must flow in the opposite direction of the current in the first wire.
Answer:
Mass Kinetic Energy and Jules
Explanation:
The train in question is big and heavy and a car is decently heavy but say a train moving at 55 mph can plow through a car and a car driving at 55mph driving at a train will be stopped dead in its tracks. This is because newtons laws of motion specifically an object in motion will stay in motion unless its opposed. The train also has a payload behind it meaning it hurts with force while a car doesn't have to much mass behind it. The train takes loner to stop for as it's acceleration as well as it's deceleration are very slow because its huge and takes a lot of force to stop it while a car is very centralized and compact when it comes to weight and its brakes are usually effective at stopping at 55 mph in about 2 to 6 seconds while a train might stay moving for a good 35 seconds. The force behind the train is immense for as even if the wheels don't spin at all the train will still move since the force behind it is great and a cars tires have a lot of grip and not a lot mass which plays into the force the car has so it can stop simply.
Given:
Amount of heat produced = 100 kcal per hour
Let's find the rate of energy production in joules.
We know that:
1 calorie = 4.184 Joules
1 kcal = 4.184 Joules
To find the rate of energy production in Joules, we have:
Therefore, the rate of energy production in joules is 418.4 kJ/h which is equivalent to 418400 Joules
ANSWER:
418.4 kJ/h
