Answer:
(a) 5142.86 m
(b) 317.5 m/s
(c) 49.3 degree C
Explanation:
m = 100 kg, Q = 1200 kcal = 1200 x 1000 x 4.2 = 504 x 10^4 J
(a) Let the altitude be h
Q = m x g x h
504 x 10^4 = 100 x 9.8 x h
h = 5142.86 m
(b) Let v be the speed
Q = 1/2 m v^2
504 x 10^4 = 1/2 x 100 x v^2
v = 317.5 m/s
(c) The temperature of normal human body, T1 = 37 degree C
Let the final temperature is T2.
Q = m x c x (T2 - T1)
504 x 10^4 = 100 x 4.1 x 1000 x (T2 - 37)
T2 = 49.3 degree C
Answer:
Silver has greater electronegativity (pull on electrons) than copper, so it will be reduced rather than oxidized. Silver ions will plate out on copper metal. Sir the coating of iron with copper surface can be referred as IRON-COPPER PLATING.
Explanation:
Iron is used for the electroplating of so copper because iron falls above copper in the electrochemical series whereas silver will fall off below the copper in electrochemical series that makes it not reliable for the electroplating purpose
Answer:
option D
Explanation:
given,
uniform length of cylinder = 1 m
diameter of the cylinder = 10 cm = 0.1 m
Eels have been recorded to spin = 14 rev/s
camera records at = 120 frames per second
time = 
angle at which eel rotate = ?
ω = 14 rev/s
ω = 14 x 2 π rad/s
ω = 28 π rad/s
angle at which eel rotate
θ = ω t
θ = 
θ = 0.733 rad
θ =
θ =
Hence, the correct answer is option D
Answer:
Velocity of Sedan = 21 m/s
Velocity of SUV = 12 m/s
Explanation:
As we know that deceleration due to friction force is given as

so we have


now the two cars comes to rest at a point which is at position of 5.39 m West and 6.43 m South
so net displacement of the car is given as


now the velocity of the two cars just after the impact is given as



direction of the motion is given as

South of West
now we can use momentum conservation as there is no external force on it
Momentum conservation in North to south direction



Similarly momentum conservation towards West direction



Answer:
6N
Explanation:
Given parameters:
Mass of object = 6kg
Initial velocity = 5m/s
Final velocity = 25m/s
Time = 30s
Unknown:
Net force acting on the object = ?
Solution:
From Newton's second law of motion:
Force = mass x acceleration
Acceleration is the rate of change of velocity with time
Acceleration =
Force = mass x
So;
Force = 6 x
= 6N