Answer:
The time taken by the brick to hit the ground, t = 0.84 s
Explanation:
Given that,
A brick falls from a height, h = 3.42 m
The initial velocity of the brick is zero.
Since the brick is under free-falling. The time equation of a free-falling body when the displacement is given is
t = 
where,
h - height from surface in meters
g - acceleration due to gravity
on substituting the values in the above equation,
t = 
= 0.84 s
Hence, time taken by the brick to hit the ground is t = 0.84 s
Answer:
C. Photosphere
Explanation:
The lights shown in the figure comes from the outermost layer of the Sun. This layer is called photosphere.
This is the layer from where the light of the Sun is radiated, before travelling through space and reaching us.
The photosphere is the coldest layer of the Sun: its surface temperature is between 4500 and 6000 K. Its width is approximately 100 km.
A characteristic of the photosphere is the presence of the sunspots, which appear as darker spots, and are regions of lower temperature caused by a concentration of magnetic flux.
Answer:
3.46 seconds
Explanation:
Since the ball is moving in circular motion thus centripetal force will be acting there along the rope.
The equation for the centripetal force is as follows -
Where, 
is the mass of the ball, 
is the speed and 
is the radius of the circular path which will be equal to the length of the rope.
This centripetal force will be equal to the tension in the string and thus we can write,
and, 
Thus, 
m/s.
Now, the total length of circular path = circumference of the circle
Thus, total path length = 2πr = 2 × 3.14 × 2 = 12.56 m
Time taken to complete one revolution = 
= 
= 3.46 seconds.
Thus, the mass will complete one revolution in 3.46 seconds.
Answer:
3136 Joules
Explanation:
Applying,
P.E = mgh.............. Equation 1
Where P.E = potential energy, m = mass of the cinder block, h = height of the platform, g = acceleration due to gravity.
From the question,
Given: m = 16 kg, h = 20 m
Constant: g = 9.8 m/s²
Substitute these values into equation 1
P.E = 16(20)(9.8)
P.E = 3136 Joules
Hence the potential energy of the cinder block is 3136 Joules
Explanation:
Velocity = displacement / time
v = √((58 m)² + (135 m)²) / (12 min × 60 s/min)
v = 0.20 m/s
