Answer:
Option D - 0.2 s
Explanation:
We are given;
Initial velocity; u = 7 m/s
Height of table; h = 1.8m
Now,since we want to find the time the car spent in the air, we will simply use one of Newton's equation of motion.
Thus;
h = ut + ½gt²
Plugging in the relevant values, we have;
1.8 = 7t + ½(9.8)t²
4.9t² + 7t - 1.8 = 0
Using quadratic formula to find the roots of the equation gives us;
t = -1.65 or 0.22
We can't have negative t value, thus we will pick the positive one.
So, t = 0.22 s
This is approximately 0.2 s
Answer:
Work done is 882000joule.
power is 29400watt.
Explanation:
given,
Mass(m)=500kg
Acceleration due to gravity(g)=9.8m/s²
Height(h)=6m
Time taken(t)=30s
Workdone=?
Power=?
now,
workdone=force*displaxement
= m*g*h
=500*9.8*6
=8,82,000joule
so, the work done by the man is 8,82,000joule.
then,
power=workdone/time taken
=8,82,000/30
=29,400watt
so, the required power to lift a load is 29,400watt.
constant non zero acceleration
Radiation compared to other potential
