Answer:
c. 0.25km
Explanation:
v=f x wavelength
3000 = 12 x wavelength
wavelength = 3000/12 = 250m
250m to km
To convert m to km, we divide by 1000
250/1000 =0.25km
wavelength = 0.25km
Answer: The gravitational acceleration on planet X is 5 N/kg
On Earth (with the gravitational accelartion g_E) the mass of 2kg will correspond to

On planet X we are told the same measure is only 10N. Since there is a proportional relationship between g and F, we can calculate g_X:

Which one if you want independent variable meaning that means variable (often denoted by x ) whose variation does not depend on that of another.
Answer:
1.6 m/s
Explanation:
First you need to find the momentums of each disc by multiplying their velocities with mass.
disc 1: 7*1= 7 kg m/s
disc 2: 1*9= 9 kg m/s
Second, you need to find the total momentum of the system by adding the momentums of each sphere.
9+7= 16 kg m/s
Because momentum is conserved, this is equal to the momentum of the composite body.
Finally, to find the composite body's velocity, divide its total momentum by its mass. This is because mass*velocity=momentum
16/10=1.6
The velocity of the composite body is 1.6 m/s.
They are trailing the same speed as it states in the question they are heeding toward each other a 70 mph <span />