Answer:
A light-year is a unit of distance. It is the distance that light can travel in one year. Light moves at a velocity of about 300,000 kilometers (km) each second. So in one year, it can travel about 10 trillion km. More p recisely, one light-year is equal to 9,500,000,000,000 kilometers
Answer:
0.4113772 s
Explanation:
Given the following :
Mass of bullet (m1) = 8g = 0.008kg
Initial horizontal Velocity (u1) = 280m/s
Mass of block (m2) = 0.992kg
Maxumum distance (x) = 15cm = 0.15m
Recall;
Period (T) = 2π√(m/k)
According to the law of conservation of momentum : (inelastic Collison)
m1 * u1 = (m1 + m2) * v
Where v is the final Velocity of the colliding bodies
0.008 * 280 = (0.008 + 0.992) * v
2.24 = 1 * v
v = 2.24m/s
K. E = P. E
K. E = 0.5mv^2
P.E = 0.5kx^2
0.5(0.992 + 0.008)*2.24^2 = 0.5*k*(0.15)^2
0.5*1*5.0176 = 0.5*k*0.0225
2.5088 = 0.01125k
k = 2.5088 / 0.01125
k = 223.00444 N/m
Therefore,
Period (T) = 2π√(m/k)
T = 2π√(0.992+0.008) / 233.0444
T = 2π√0.0042910
T = 2π * 0.0655059
T = 0.4113772 s
The answers are B, C, E and F.
Atoms from an element is mostly made of protons, neutrons, and electrons. Proton numbers are like a class number for each element. Each element has their own and they're all different. And the number of protons are equal to the number of electrons. Therefore, B is correct.
Isotopes. It's different atoms from a same element that has the same number of protons but different number of neutrons. For example in hydrogen, there's 3 Isotopes for hydrogen. Therefore, C is correct.
Again, proton for the same element is never changed, even if they're different Isotopes. So, E is correct.
Isotopes, again, different elements may have different Isotopes. Some has only 1, others may have a few or more. So, F is correct too.
Answer:
Average speed of Elain = 60 km/h
Explanation:
Total Distance covered by Jack = 360km
Average Speed of Jack = 80 km/h
Time taken by Jack to complete his journey = Distance / Average speed = 360 km / 80 km/h
Time taken by Jack to complete his journey = 4.5 hours
As it is given the both Jack and Elain travelled the same amount of distance:
Total distance travelled by Elain = 360 km
It is given that Elain took 1.5 hourse more than Jack to cover the distance, so Time taken by Elain to cover the distance is = 4.5 hours + 1.5 hours = 6 hours
Average speed of Elain = Distance/ time = 360 km / 6 hours
Average speed of Elain = 60 km/h
Answer: A
Explanation: STEP BY STEP
