Answer:
375J of wasted energy
Explanation:
Efficiency=work output/work input×100%
50=w.o/750×100
750×50=100w.o
w.o=750×50/100
w.o=75×5
w.o=375J
Wasted energy=750J-375J
=375J
Aliter
If the machine is 50% efficient then it is also 50% inefficient
50%×750J=375J
When air resistance<span> acts, acceleration during a fall </span>will<span> be less than g because </span>air resistance affects<span> the motion of the falling </span>objects<span> by slowing it down. </span>Air resistance<span> depends on two important factors - the</span>speed<span> of the </span>object<span> and its surface area. Increasing the surface area of an </span>object<span> decreases its </span>speed<span>.</span>
Answer:
v=32.49 m/s
Explanation:
Given that
Distance ,d= 66 m
Initial speed of the car ,u = 0 m/s
Coefficient of friction ,μ = 0.8
Lets take the total mass of the car = m
The acceleration of the car is given as
a = μ g ( g= 10 m/s² )
Now by putting the values in the above equation we get
a= 0.8 x 10 m/s²
a= 8 m/s²
We know that ,final speed is given as
v²= u ²+ 2 a d
Now putting the value
v²=0² + 2 x 8 x 66
v²= 1056
v=32.49 m/s
If the sun generates any mechanical waves, none of them
have ever reached us, because only electromagnetic waves
can travel through empty space.
