Answer:
783.2 N.m or Joules
Explanation:

Work done when a force F is applied to move an object by a displacement d meters
where cos(Ф) is the angle between applied force F and displacement d
Since the weightlifter is applying the force upward and the set of weight also move upward therefore, both are in same direction hence angle will be zero.
Now lets substitute the given values into the work equation:

since cos(0)=1


or

Since the unit of Force is Newton (N) and the unit of displacement is meters (m) therefore, unit of work done will be N.m
Note: 1 N.m is equivalent to 1 joule
Answer:
37.125 m
Explanation:
Using the equation of motion
s=ut+0.5at^{2} where s is distance, u is initial velocity, t is time and a is acceleration
<u>Distance during acceleration</u>
Acceleration, a=\frac {V_{final}-V_{initial}}{t} where V_{final} is final velocity and V_{initial} is initial velocity.
Substituting 0.0 m/s for initial velocity and 4.5 m/s for final velocity, acceleration will be
a=\frac {4.5 m/s-0 m/s}{4.5 s}=1 m/s^{2}
Then substituting u for 0 m/s, t for 4.5 s and a for 1 m/s^{2} into the equation of motion
s=0*4.5+ 0.5*1*4.5^{2}=0+10.125
=10.125 m
<u>Distance at a constant speed</u>
At a constant speed, there's no acceleration and since speed=distance/time then distance is speed*time
Distance=4.5 m/s*6 s=27 m
<u>Total distance</u>
Total=27+10.125=37.125 m
Answer:
v = 7934.2 m/s
Explanation:
Here the total energy of the Asteroid and the Earth system will remains conserved
So we will have

now we know that





now from above formula

now we have

now plug in all data


Answer: B
Explanation:
An unbalanced force (net force) acting on an object changes its speed and/or direction of motion. An unbalanced force is an unopposed force that causes a change in motion.
The third option seems correct. Using any bag more than once will help in decreasing the carbon foot print.
This isds beause, if you use paper bag once only, then paper bag is being utilised and more and more paper is being used. So the best way is to use the bag more than once, whichever bag u are using.