Answer:
Option d) only its mechanical energy is conserved
Explanation:
Since, mechanical energy of a system is the sum of its kinetic energy and potential energy.
Potential energy depends directly on height while kinetic energy depend on the speed of the body.
When the rock is dropped its potential energy decreases while its kinetic energy increases while the potential energy is maximum at the top and kinetic energy was zero.
Therefore, these two energies are inter convertible and when one increases the other decreases and vice-versa keeping the overall mechanical energy conserved.
The variables that show a direct relationship are :
- The speed of a car and the distance traveled
- Number of students in a cafeteria and the amount of food consumed
- The distance a planet is from the sun and that planet's temperature
- The mass of a space shuttle and its acceleration through space
In direct relationship, when one factor is increased/decreased , it will directly cause the other factor to be increased/decreased
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
Answer:F=11.76 kN
Explanation:
Given
mass of rocket
Force F is applied up to a height of 100 m then it is shut off
final velocity v up to which force is applied is given by
After this rocket continues to move to a maximum height under the action of gravity
using
thus Force is