Answer:
9.12267515924 m/s²
Explanation:
Here the moment created by the wheels and the moment created by the center of gravity will balance each other.
h = Height of the center of mass = 78.5 cm
d = Distance from back wheel to the center of mass = 
g = Acceleration due to gravity = 9.81 m/s²
a = Horizontal acceleration
The equation is of the form

The horizontal acceleration of the motorcycle that will make the front wheel rise off the ground is 9.12267515924 m/s²
Explanation :
Work is done when a force is applied to create a displacement on an object.
Thus, the work done depends on the two factors i.e.
(1) Applied force (F)
(2) Distance or displacement (d)
Mathematically, work done is 
It also depends on the angle between the force and the displacement.

For example,
A person carries a weight of 20 kg and lifts it on his head 1.5 m above the surface. So, the work done by him on the luggage will be:

or


So, 
Hence, the work done by him on the luggage is 294 Joules.
Answer:
Work done will be 2.205 j
Explanation:
We have given that the spring is compressed b 37.5 cm
So d = 0.375 m
Mass of the block m = 600 gram = 0.6 kg
Acceleration due to gravity 
Gravitational force on the block 
Now we know that work done is give by 
answer
option d is the correct answer
explanation
as we know frequency is equal to 1 /t
f= 457 Hz
t=1
SO, 1/457
=0.0022sev