Answer:
8 signals received by twin A during the trip.
Explanation:
Given that,
Distance = 12 light year
Speed = 0.6 c
Time = 1 year
We need to calculate the time by A
Using formula of time

Put the value into the formula


Similarly,
The expression for distance cover by A



We need to calculate the time
Using formula of time



We need to calculate the signals received by twin A
Using formula for number of signals

Put the value into the formula


Hence, 8 signals received by twin A during the trip.
By Snell's law:
η = sini / sinr. i = 25, η = 1.33
1.33 = sin25° / sinr
sinr = sin25° / 1.33 = 0.4226/1.33 = 0.3177 Use a calculator.
r = sin⁻¹(0.3177)
r ≈ 18.52°
Option A.
God's grace.
Answer:
The maximum height attained by the object and the number of seconds are 128 ft and 4 sec.
Explanation:
Given that,
Initial velocity u= 128 ft/sec
Equation of height
....(I)
(a). We need to calculate the maximum height
Firstly we need to calculate the time

From equation (I)




Now, for maximum height
Put the value of t in equation (I)


(b). The number of seconds it takes the object to hit the ground.
We know that, when the object reaches ground the height becomes zero




Hence, The maximum height attained by the object and the number of seconds are 128 ft and 4 sec.
Since, the options are not given the question is incomplete the complete question is as follows.:
Which of the following is a major way in which oceans contribute to weather systems?
provide a diverse habitat for many organisms
experience changes in amounts of dissolved salts
store and transport the Sun's heat energy
reach depths that can be as much as 12000 meters
Answer: Store and transport the Sun's heat energy.
Explanation:
Oceanic currents are just like a conveyor belt. It helps in transportation of the warm water and the precipitation from the equator to the poles and the cold water in the poles towards the tropics. This way the oceans counteract the uneven distribution of the radiation of sun that reaches upto the surface earth. This will regulate the global climate.
Answer:
a = -5.10 m/s^2
her acceleration on the rough ice is -5.10 m/s^2
Explanation:
The distance travelled on the rough ice is equal to the width of the rough ice.
distance d = 5.0 m
Initial speed u = 9.2 m/s
Final speed v = 5.8 m/s
The time taken to move through the rough ice can be calculated using the equation of motion;
d = 0.5(u+v)t
time t = 2d/(u+v)
Substituting the given values;
t = 2(5)/(9.2+5.8)
t = 2/3 = 0.66667 second
The acceleration is the change in velocity per unit time;
acceleration a = ∆v/t
a = (v-u)/t
Substituting the values;
a = (5.8-9.2)/0.66667
a = -5.099974500127
a = -5.10 m/s^2
her acceleration on the rough ice is -5.10 m/s^2