' D ' is the only correct statement on the list.
Electromagnetic waves are capable of traveling through
many substances, and they're also capable of traveling
through vacuum. Mechanical waves can't travel in vacuum.
Answer:
- 0.5 m/s
Explanation:
(1) Acceleration = change in velocity / time
(2) Change in velocity = (Final velocity - Initial velocity)
We know:
acceleration = 1.5 m/s/s
time = 5 seconds
final velocity = 7 m/s
x = initial velocity)
1.5 = ( 7 - x ) / 5
1.5 x 5 = ( 7 - x )
7.5 = 7 - x
x = -0.5 m/s
You can check the answer by plugging in the values to equation (1).
Answer:
Explanation:
Laser angle with water surface is given by: Tan α = 1/2.0= 0.5/
α = 26.56°
Laser angle with Normal = 90 - 26.56 = 63.44 °
Assuming a red laser, refractive index in water is 1.331.
Angle of refraction in water is given by:
Ref Ind = Sin i / Sin r
1.331 = Sin 63.44 / Sin r
Sin r = 0.8945 / 1.331 = 0.6721
Angle r = 42.22°
For the path in water:
Tan 42.22 = x / 3.2
x = 2.9m where x is the lateral displacement of the laser ince it hits the water
So the goggles are 2.0 + 2.9 = 4.9 m from edge of pool
Find the number of hours by dividing the distance by mph. The number of hours will be to the left of the decimal point:
250 miles / 65 mph
= 3.846153846
= 3 hours
2) Find the number of minutes by multiplying what is remaining from step 1 by 60 minutes. The minutes will be to the left of the decimal point:
0.846153846 x 60
= 50.76923076
= 50 minutes
3) Find the number of seconds by multiplying what is remaining from step 2 by 60 seconds. The seconds will be to the left of the decimal point:
0.76923076 x 60
= 46.1538456
= 46 seconds
So 3 hours 50 mins and 46 seconds
