Answer:
His speed, in metres per second, is approximately 10m/s. The correct option is B.
Explanation:
Speed is defined as the rate in which an object cover a distance in a given time. It is measured in meters per second ( m/s). From the question, the jogger covered a distance of 3Km which when converted to meter is 3000meters in a given time 5 minutes which is 300seconds. The calculation of his speed in meter per second is shown below:
Distance= 3Km to meters ( as 1000meters = 1Km). Therefore 3× 1000 = 3000m
Time= 5 minutes to seconds ( as 1 minute = 60 Seconds). Therefore 5× 60= 300.
Speed= distance/ time
= 3000/300
= 10m/s
Therefore his speed, in metres per second, is approximately 10.
Answer: Start at the top of the hill.
Explanation:
The options include:
a. Start at the bottom of the hill.
b. Start at the top of the hill.
c. Start in the middle of the hill.
Sled racing is simply a winter dog sport racing. Since Robb wants to win the next sled race, the advice that'll be given to him is that he should start at the top of the hill.
Other options such as starting at the bottom of the hill or the middle of the hill are wrong.
Relatively hot objects emit visible light.
Some examples:
==> the wire coils in the toaster;
==> the spoon that you stuck in the flame on the stove;
==> the fine wire in the lightbulb when current goes through it.
VERY radioactive objects also do that. But if you're actually
standing there watching an object that's THAT radioactive,
then you're in big trouble.
If a star collapses to a tenth its size, gravitation at its surface increases by 100 times as much.
The contraction of an astronomical object caused by its own gravity, which tends to pull stuff inward toward the center of gravity, is known as gravitational collapse. A cloud of interstellar matter gradually collapses under the influence of gravity to form a star. The temperature rises as a result of the compression brought on by the collapse until thermonuclear fusion takes place in the star's core. At this point, the collapse gradually comes to an end as the outward heat pressure equalizes the gravitational forces. Following that, the star is in a condition of dynamic equilibrium. A star will repeatedly collapse once all of its energy sources have been used up until it reaches a new equilibrium condition.
To learn more about Star:
brainly.com/question/24493066
#SPJ4
For idea gases, volume is directly proportional to temperature. That is, an increase in temperature leads to increase in volume and vice versa.
Therefore,
V1/T1 = V2/T2 => T2 = (V2*T1)/V1
Assuming that the balloon is spherical in shape,
V= 4/3*pi*R^3.... In the formula for calculating T2, 4/3*pi cancels out.
R1 = 30/2 15 cm; R2 = 30.5/2 = 15.25 cm; T1 = 20+273.15 =293.15 K
Therefore,
T2 = (R2^3*T1)/R1^3 = (15.25^3*293.15)/15^3 = 308.05 K = 34.9 °C
