Answer:
C
Explanation:
If the theory were to be proved you you need to repeat the experiment over and over again so that way you can prove that it is true wuth the same results.
Answer:
Concrete
Explanation:
The speed at which sound propagates is medium dependent. As one of the forms of mechanical waves, sound requires a material medium for propagation from place to place.
- Sound travels with the least speed in air because air particles are far apart and they are randomized.
- Sound travels with the greatest speed in solids. Concrete is the only solid material given in the choice.
The speed of sound increases from air to liquid and to solid.
Answer:Due to change in direction
Explanation:
Given
Initially train has traveled a 100 km in North and after exchanging some railroad cars, it traveled 100 in south.
The velocity of the train changes as it direction of motion changes. Velocity is the vector quantity which require direction and magnitude for its reperesentation.
Answer:
option C
Explanation:
given,
mass of water = 4 Kg
Water is heated to = 800 W
time of immersion = 10 min
= 10 x 60 = 600 s
using equation of specific heat
Q = m S ΔT
S is the specific heat capacity of water which is equal to 4182 J/kg°C.
and another formula of heat
Q = Pt
now,
P t = m S ΔT
800 x 600 = 4 x 4182 x ΔT
ΔT = 29° C
temperature increased is equal to ΔT = 29° C
Hence, the correct answer is option C
