Answer:
10.6 s
Explanation:
Given that a girl is running the 200 m dash. She starts by acceleration at 8m/s^2 for 7s. Then continues at this speed until the end of the race. How long did it take for her to complete the race?
Solution.
If she accelerated for 7s, the velocity at which she accelerated will be:
Acceleration = velocity/time
8 = V/7
Make V the subject of the formula by cross multiplying.
V = 8 × 7
V = 56 m/s
She maintains the speed through out the journey.
Speed = distance/time
Make time the subject of formula
Time = distance/speed
Time = 200 / 56
Time = 3.57s
Therefore, she will complete the race by 7 + 3.6 = 10.6 s
Answer:
C. His victory against a superior British foe inspired the American troops.
Explanation:
John Paul Jones is considered the hero in the Revolutionary War. He is known as the Father of the US Navy.
In the Revolutionary War, Jones sided with the American colonists against the British and took hold of naval ships. In 1779, when the British warship <em>Serapis</em> was in conflict with the American warship <em>Bon Homme Richard, </em>Jones plugged the American warship with the Britisher's warship and tossed a grenade into the opponent warship. Thus when Jones was victorious in the war, this boosted the American spirits for the war.
Therefore, option C is the correct answer.
Answer:
The wavelength will be 4 cm, frequency will be 4.66 Hz and wave speed is 18.6 cm/sec
Explanation:
Given:
No. of crest = 13
No. of trough = 15
Time = 3 seconds
Hence, 1 crest or 1 trough = 
therefore,
13 C + 15 T = 
=
Time given 3 seconds
= 
2 cm distance is travelled is time period
Again wave will travel in 1 T = 4 cm
wave speed v =
= 
= 18.6 cm/s
Answer:
Explanation:
Examples are;
Ultraviolet light from sun.
Heat from a stove burner.
X-ray from an x-ray machine.
Alpha particle emit from a radio active decay of uranium.
Sound waves from your stereo.
Microwave from micro oven.
ultraviolet light from a black light.
Gamma radiations from a supernova.
AND MANY MORE.
Answer:
t = 2.58*10^-6 s
Explanation:
For a nonconducting sphere you have that the value of the electric field, depends of the region:
k: Coulomb's constant = 8.98*10^9 Nm^2/C^2
R: radius of the sphere = 10.0/2 = 5.0cm=0.005m
In this case you can assume that the proton is in the region for r > R. Furthermore you use the secon Newton law in order to find the acceleration of the proton produced by the force:
Due to the proton is just outside the surface you can use r=R and calculate the acceleration. Also, you take into account the charge density of the sphere in order to compute the total charge:
with this values of a you can use the following formula:
hence, the time that the proton takes to reach a speed of 2550km is 2.58*10^-6 s
