A book is pushed with an initial horizontal velocity of 5.0 meters per second off the top of a desk. What is the initial vertica
1 answer:
Answer:
The Initial vertical velocity is zero
Explanation:
Given that,
A book is pushed with an initial horizontal velocity, Vx = 5 m/s
According to projectile motion, the horizontal component of velocity i.e., in X-axis remains the same though out its path.
The vertical velocity varies i.e., the velocity towards the Y- axis.
The velocity of the falling book in its trajectory is the resultant velocity. Due to the action of gravity, it keeps on increasing with time.
The resultant velocity is given by relation
where
gt = Vy - vertical velocity
g - acceleration due to gravity
t - time
Since, the initial horizontal velocity at that instant is equal to the resultant velocity.
Vx = 5 m/s
= 5 m/s
So, on substituting in the above equation
Vy = 0 m/s
Therefore, the initial vertical velocity is equal to zero
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Answer:
1) 0.51 seconds.
2) 1.45 m/s.
Explanation:
given, height from which cat falls = 1.3 m
we know that, s = ut + at².
here if we consider cat moment only in downward direction,
intial velocity of cat in downward direction , u = 0.
so, time, t = .
⇒ t = = 0.51 seconds.
t = 0.51 seconds.
now, consider cat moment only in forward direction
s = ut , since acceleration is zero in forward direction
⇒ u = .
so, u = = 1.45 m/s .
Answer:
Top: PE = max, KE = 0
Middle: PE = half, KE = half
Bottom: PE = 0, KE = max
Explanation:
The potential energy of an object is the energy possessed by the object due to its location; it is given by
where
m is the mass of the object
g is the acceleration due to gravity
h is the height of the object from the ground
The kinetic energy of an object is the energy possessed by the object due to its motion; it is given by
where
v is the speed of the object
Now we analyze the three situations for the boy on the bycicle:
Top of the hill: here h (the height) is maximum, so the potential energy is maximum, while the speed is zero, therefore the kinetic energy is zero.
Middle of the hill: here h (the height) is half of the initial value, therefore the potential energy is also half of the initial potential energy. According to the law of conservation of energy, the total mechanical energy (potential+kinetic) is constant: this means that also the kinetic energy is half of the initial potential energy.
Bottom of the hill: here h is zero, therefore the potential energy is now zero. As a result, all the mechanical energy has been converted into kinetic energy, therefore the kinetic energy is maximum and it is equal to the potential energy of the boy when he was at the top.
Answer:
Truck will be at a distance of 720 m
Explanation:
Speed of the truck is given as 90 m/sec
Time for which truck travel t = 10 seconds
We have to find the distance that how much truck travel in 8 sec with speed of 90 m/sec
We know that distance is given by
So distance traveled by truck in 8 sec will be equal to
So truck will be at a distance of 720 m