Answer:
(a) 5.7 s
(b) 39 m/s
Explanation:
(a) u = 18 m/s
At the maximum height, the final velocity of ball is zero. lte teh time taken by the ball to go from 50 m height to maximum height is t.
use first equation of motion.
v = u + g t
0 = 18 - 10 x t
t = 1.8 s
Let the maximum height attained by the ball when it thrown from 50 m height is h'.
Use third equation of motion
v^2 = u^2 + 2 g h'
0 = 18^2 - 2 x 10 x h'
h' = 16.2 m
Total height from the ground H = h + h' = 50 + 16.2 = 76.2 m
Let t' be the time taken by the ball to hit the ground as it falls from maximum height.
use third equation of motion
H = ut + 1/2 x g t'^2
76.2 = 0 + 1/2 x 10 x t'^2
t' = 3.9 s
Total time taken by the ball to hit the ground = T = t + t' = 1.8 + 3.9 = 5.7 s
(b) Let v be the velocity with which the ball strikes the ground.
v^2 = u^2 + 2 g H
v^2 = 0 + 2 x 10 x 76.2
v = 39 m/s
Answer:
c. Clockwise
Explanation:
As per FARADAY's the rate of change in magnetic flux linked with a coil will induce EMF in the coil and this will result the induce current in the coil.
Here we know that the direction of induced current in the closed loop is in such a way that the magnetic flux due to induced current always oppose the flux due to which it is induced
So we can say that if the flux linked with the coil will increase with time then flux of induced current will be in opposite direction to oppose the increasing flux.
So here when magnetic field becomes stronger then the induced current is in such a way that will always oppose the increasing flux of magnetic field
So we will say that correct answer will be
c. Clockwise
Answer:
Explanation:
<u>Accelerated Motion</u>
It occurs when an object changes its speed over time. If the changes in speed are uniform, then the acceleration is constant, positive if the speed increases, negative if the speed decreases.
The acceleration is calculated as follows:
The aeroplane starts with a speed of vo=62 m/s and reaches a speed of vf=6 m/s in t=35 s.
The acceleration is:
Answer:
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