The change in mechanical energy caused by the dissipative resistance force is equal to, difference between the potential energy and kinetic energy of the object.
Potential energy of the object, P.E = mgh
m is mass of the object = 10 kg
g is acceleration due to gravity = 9.8 m/s²
h= height from which it is dropped =50 m
Substituting the value we get,
P.E = 10×9.8×50 = 4900 J
Kinetic energy of the object, K.E = 
v is the velocity of the object = 26 m/s²
K.E = (1/2)×10×(26)²
= 3380 J
Change in mechanical energy caused by dissipative force = P.E ₋ K.E
= 4900 ₋ 3380 = 1520 J
Answer:
the energy absorbed is 4.477 x 10⁶ J
Explanation:
mass of the liquid, m = 13 kg
initial temperature of the liquid, t₁ = 18 ⁰C
final temperature of the liquid, t₂ = 100 ⁰C
specific heat capacity of water, c = 4,200 J/kg⁰C
The energy absorbed is calculated as;
H = mcΔt
H = mc(t₂ - t₁)
H = 13 x 4,200(100 - 18)
H = 4.477 x 10⁶ J
Therefore, the energy absorbed is 4.477 x 10⁶ J
Answer:
D. half as much
Explanation:
let m and M be the mass of the planets and r be the distance between them.
then: the force of attraction between them is given by,
F = G×m×M/(r^2)
if we keep one mass constant and double the other and also double the distance between them.
the force of attraction becomes:
F1 = 2G×m×M/[(2×r)^2]
= 2G×m×M/[4×(r)^2]
= (1/2)G×m×M/(r^2)
= 1/2×F
therefore, when you double one mass and keep the other mass constant and double the distance between the masses you decrease the force by a factor of 1/2.
Answer:
Explanation:
The question relates to Doppler effect and beat.
The observer is moving towards the reflected sound so apparent frequency will be increased
f = f₀ x (V + v₁) / (V - v₂)
f is apparent frequency , f₀ is real frequency , V is velocity of sound , v₁ is velocity of observer and v₂ is velocity of source . Here
v₁ = v₂ = vp as both observer and source have same velocity
f = f₀ x (V + v₁) / (V - v₂)
205 +5 = 205 x (344 +vp)/ ( 344 - vp)
1.0234 = (344 +vp)/ ( 344 - vp)
= 352 - 1.0234vp = 340+vp
12 / 2.0234vp
vp = 6 m /s approx.
Night hunting animals have more rod cells in their retinas which allows them to see better in the dark.
