Answer:
- 1 m/s ( here (-) means the opposite direction of A)
Explanation:
Let m1=2kg, m2=2kg,u1= 3m/s,u2= -2 m/s, v1= 1m/s
m1u1+m2u2= m1v1+m2v2
2×3+2×(-2) = 2×1 + 2x
2= 2(1+x)
x = -1
Hope it helps
Answer:
D. As the angle changes, the differences in paths among light reflected from different surfaces change, resulting in constructive interference for a different color.
Explanation:
The color of body of butterfly is not due to pigment . It is due to optical effect called interference . The same phenomenon is responsible for coloration of films of oil on water or soap bubble etc. Here interference is caused by multiple slits . As the angle changes, the differences in paths among light reflected from different surfaces change, resulting in constructive interference for a different color.
Answer:
Explanation:
1 ) Total mechanical energy of the car at the height of 10 m
1/2 mv² + mgh
.5 x 1800 x 25² + 1800 x 9.8 x 10 m
= 562500 + 176400
738900 J
If v be the velocity at the bottom ,
Total energy of the car at the bottom
1/2 m v² + 0
Applying conservation of energy
1/2 mv² = 738900
.5 x 1800 v² = 738900
v = 28.65 m /s
Energy required by car to ascend height of 15 m
1800 x 9.8 x 15
= 264600 J
b )
This energy is more that total energy of the car at the top that is 738900 J
so car can easily reach gas station .
If V be the velocity at the gas point
Total energy at the gas point
1/2 m V² + 264600
Applying conservation of energy
1/2 m V² + 264600 =738900
.5 x 1800 x V² = 474300
V = 22.95 m / s
d ) If R be the normal reaction at the bottom
net force
R - mg = m v² / r
R = m ( g + v² / r )
1800 ( 9.8 + 28.65² / 5 )
R = 313136 N
This problem is to let you practice using Newton's second law of motion:
Force = (mass) x (acceleration)
-- The airplane's mass when it takes off (before it burns any of its load of fuel) is 320,000 kg.
-- The force available is (240,000 N/per engine) x (4 engines) = 960,000 N.
-- Now you know ' F ' and ' mass '. Use Newton's second law of motion to calculate the plane's acceleration.
The flow of Direct current (DC) is constant and flows in one direction. Most digital electronics make use of DC. Alternating current (AC) periodically flows in reverse and is mostly used to deliver power to houses, buildings and the like. With that alone, you can already rule out A, C and D.
The answer would then be B. constant, periodically reversing.
