Choice-B is the correct one.
-- The atomic number is the number of protons in the nucleus.
-- Each proton in the nucleus is usually matched by one electron in the 'cloud'.
-- The addition of a proton OR a neutron increases the mass number by 1 .
-- Electrons have such small mass that they don't figure into the atomic mass at all.
Answer:
0.011 m.
Explanation:
Energy stored in the spring = Energy of the projectile.
1/2ke² = mgh ................ Equation 1
Where k = spring constant, e = extension or compression, m = mass of the projectile, g = acceleration due to gravity, h = height.
make e the subject of the equation
e = √(2mgh/k)............................. Equation 2
Given: k = 12 N/cm = 1200 N/m, m = 15 g = 0.015 kg, h = 5.0 m
Constant: g = 9.8 m/s²
Substitute into equation 2
e = √(2×0.015×5/1200)
e = √(0.15/1200)
e = √(0.000125)
e = 0.011 m.
The question is poor. Light doesn't refract on its way THROUGH anything. It refracts at the boundary BETWEEN two different media. The effect is greatest where the ratio of the speeds of light in the two media is greatest. On your list, that would be at the boundary between air or space and glass.
Answer:
I reckon towards b. Let me know if im right
Answer:
Explanation:
a )
While breaking initial velocity u = 62.5 mph
= 62.5 x 1760 x 3 / (60 x 60 ) ft /s
= 91.66 ft / s
distance trvelled s = 150 ft
v² = u² - 2as
0 = 91.66² - 2 a x 150
a = - 28 ft / s²
b ) While accelerating initial velocity u = 0
distance travelled s = .24 mi
time = 19.3 s
s = ut + 1/2 at²
s is distance travelled in time t with acceleration a ,
.24 = 0 + 1/2 a x 19.3²
a = .001288 mi/s²
= 2.06 m /s²
c )
If distance travelled s = .25 mi
final velocity v = ? a = .001288 mi / s²
v² = u² + 2as
= 0 + 2 x .001288 x .25
= .000644
v = .025 mi / s
= .0025 x 60 x 60 mi / h
= 91.35 mph .
d ) initial velocity u = 59 mph
= 86.53 ft / s
final velocity = 0
acceleration = - 28 ft /s²
v = u - at
0 = 86.53 - 28 t
t = 3 sec approx .
