Answer : The time required is, 16.1 minutes.
Explanation :
First we have to calculate the amount of heat required to increase the temperature is:


where,
Q = amount of heat required = ?
m = mass
= density of air = 
V = volume of air
C = specific heat of air = 
= change in temperature = 
Now put all the given values in above formula, we get:



Now we have to calculate the time required.
Formula used :

where,
t = time required = ?
Q = amount of heat required = 
P = power = 1500 W
Now put all the given values in above formula, we get:


Thus, the time required is, 16.1 minutes.
Answer:
D)
The energy of the wave moves perpendicular to the direction the wave travels.
Explanation:
I had this question on USA test prep and this was the correct answer
The correct answer to the question is : 4000 N
EXPLANATION:
As per the question, the mass of the roller coaster is given as m = 2000 kg
The acceleration of the roller coaster is given as a = 2m/s2
We are asked to calculate the net force acting on the roller coaster.
From Newton's second laws of motion,we know that net external force acting on a particle is equal to the product of mass with acceleration of the particle.
Mathematically it is written as-
F = ma
Hence,net force acting on the roller coaster is calculated as-
F = 2000Kg×2m/s2
= 4000 N.
Here, Newton (N) is the unit of force.
Hence,net force acting on the roller coaster is 4000 N.
Answer:
Maximum height will be 
Explanation:
We have given initial velocity through which basketball is thrown 
Acceleration due to gravity 
At maximum height velocity will be zero
So final velocity v = 0 m /sec
According to third equation of motion 
( Negative sign is due to upward acceleration )

Answer:
Explanation:
The amplitude is extraneous information for this question.
Period (T) is simply a measure of time (how long it takes to complete a full cycle).
The frequency (f), is the reciprocal (how many cycles it can complete per unit of time).
The frequency reported is 12Hz. Hz is a unit meaning "cycles per second"
Thus 12cycles = 1second.
To find the number of seconds per cycle, simply create the other unit fraction and simplify:

