Answer:
Explanation:
Since the roundabout is rotating with uniform velocity ,
input power = frictional power
frictional power = 2.5 kW
frictional torque x angular velocity = 2.5 kW
frictional torque x .47 = 2.5 kW
frictional torque = 2.5 / .47 kN .m
= 5.32 kN . m
= 5 kN.m
b )
When power is switched off , it will decelerate because of frictional torque .
The correct answer to the question is: A) miles/hour and B) metre/ second.
EXPLANATION:
Before answering this question, first we have to understand speed.
The speed of a body is defined as the rate of distance travelled or the distance travelled by a body per unit time.
Hence, it is a derived quantity which is obtained from distance and time.
The unit of distance can be metre, miles, and the unit of time can be second, minutes or hour.
As speed is the distance covered per unit time, the perfect units will be miles/hour and metre/second.
Hence, the correct options are first and second.
Answer: The distance is 723.4km
Explanation:
The velocity of the transverse waves is 8.9km/s
The velocity of the longitudinal wave is 5.1 km/s
The transverse one reaches 68 seconds before the longitudinal.
if the distance is X, we know that:
X/(9.8km/s) = T1
X/(5.1km/s) = T2
T2 = T1 + 68s
Where T1 and T2 are the time that each wave needs to reach the sesmograph.
We replace the third equation into the second and get:
X/(9.8km/s) = T1
X/(5.1km/s) = T1 + 68s
Now, we can replace T1 from the first equation into the second one:
X/(5.1km/s) = X/(9.8km/s) + 68s
Now we can solve it for X and find the distance.
X/(5.1km/s) - X/(9.8km/s) = 68s
X(1/(5.1km/s) - 1/(9.8km/s)) = X*0.094s/km= 68s
X = 68s/0.094s/km = 723.4 km
High temperature gives the hydrogen atoms enough energy to overcome the electrical repulsion between the protons. Fusion requires temperatures of about 100 million Kelvin (approximately six times hotter than the sun's core).
Answer:
0.25miles/min
Explanation:
Instantaneous speed of a person or an object is its speed at a particular moment usually at a period of time.
The speedometer of a car reports the instantaneous speed.
It can be mathematically expressed as;
Instantaneous speed = 
At 20min the distance covered is 5miles;
Instantaneous speed = 
= 0.25miles/min
