Answers
The car's forward motion is opposed by the friction between the road and the tires and by the resistance of the air.
The directions arrow<span> is </span>always<span> going the wrong </span>way<span>.</span>
The mechanical advantage of a simple machine is the measure of its amplified force gain.
The mechanical advantage is defined as the force amplified by a machine to the force required to generate such output.

are the amplified force and applied force. We may also consider them as output and input force.
In the given question, the force given to the steering wheel is 50 N.
The output force produced by the steering wheel is 3750 N.
Hence the mechanical advantage will be-


[ans]
Answer:
(a) 
(b) 
(c) K.E. = 21.168 J
(d) 
Explanation:
Given:
- mass of a block, M = 3.6 kg
- initial velocity of the block,

- constant downward acceleration,

That a constant upward acceleration of
is applied in the presence of gravity.
∴
- height through which the block falls, d = 4.2 m
(a)
Force by the cord on the block,



∴Work by the cord on the block,


We take -ve sign because the direction of force and the displacement are opposite to each other.

(b)
Force on the block due to gravity:

∵the gravity is naturally a constant and we cannot change it


∴Work by the gravity on the block,



(c)
Kinetic energy of the block will be equal to the net work done i.e. sum of the two works.
mathematically:


K.E. = 21.168 J
(d)
From the equation of motion:

putting the respective values:

is the speed when the block has fallen 4.2 meters.
The angle of reflection is equal to angle of incidence so the angle of reflection is also 32°.