Acceleration = (change in speed) / (time for the change).
Change in speed = (15 - 30) = -15 km/hr
Time for the change = 4 sec
Acceleration = (-15 km/hr) / (4 sec) = -3.75 km/hr per second .
Is that a lot ? Not much ?
Let's convert it to a unit that we can think about:
(-15 km/hr) x (1,000 m/km) x (1 hr / 3,600 sec) =
(-15 x 1,000) / (3,600) = -(4 and 1/6) m/sec .
So the acceleration of the bus is -(4 and 1/6) m/sec² .
The negative sign means that it slowed down.
(4 and 1/6) m/sec² is about 42% of the acceleration of gravity ...
the acceleration the bus would have if it drove off of a cliff.
When the car or the bus you're riding in slows down at that rate,
you feel 42% of your weight pulling you forward against your
seat belt. That's quite a drastic acceleration !
Answer:
Gas giants rotate faster than those of earth .
Answer:
d) Law of Conservation of Energy
Explanation:
The first law of thermodynamics states that energy can neither be created nor destroyed; energy can only change from one form to another.
For multiple choice you can use an elimination method. If you remember the law then you know it's not A or C because "energy cannot be created nor destroyed", and it's not B because it has nothing to do with mass.
Hope this helps!
Hydrogen has the smaller, lighter, simpler nucleus.
Helium has the larger, heavier, more complex nucleus.
Hydrogen nuclei are fused to form helium nuclei.
When that happens, energy is released.
Answer:
Volume of balloon = 1000 cm^3
Explanation:
The head of a normal person can be assumed as a sphere with radius 10 cm.
Volume of sphere 
, where r is the radius.
We have approximate radius = 10 cm.
Approximate volume of head 
In the given options the closest value to the approximate volume is 1000 cm^3.
So, volume of head = Volume of balloon = 1000 cm^3
