A wooden block of mass 10 g is dropped from the top of a tower 100 m high. Simultaneously, a bullet of mass 10 g is fired from the foot of the tower vertically upwards with a velocity of 100 m/s. If the bullet is embedded in it, how high will the block rise above the top of tower before it starts falling?
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|
a) |
75 m |
b) |
85 m |
c) |
80 m |
d) |
10 m |
Question ID - 100305 | SaraNextGen Answer A wooden block of mass 10 g is dropped from the top of a tower 100 m high. Simultaneously, a bullet of mass 10 g is fired from the foot of the tower vertically upwards with a velocity of 100 m/s. If the bullet is embedded in it, how high will the block rise above the top of tower before it starts falling? )
a)
75 m
b)
85 m
c)
80 m
d)
10 m
A wooden block of mass 10 g is dropped from the top of a tower 100 m high. Simultaneously, a bullet of mass 10 g is fired from the foot of the tower vertically upwards with a velocity of 100 m/s. If the bullet is embedded in it, how high will the block rise above the top of tower before it starts falling? )
|
a) |
75 m |
b) |
85 m |
c) |
80 m |
d) |
10 m |
(a)
The bullet and block will meet after time
During this time, distance travelled by the block,
Distance travelled by the bullet,
m
Velocity of the bullet before collision,
m/s
Velocity of the block before collision,
m/s
Let 
be the combined velocity after collision
According to the law of conservation of momentum,
or 
(Velocity in upward direction is considered positive)
Solving, we get 
m/s
Maximum height risen by the block 
m
Height reached above the top of the tower is
m
