Bohr described the Planetary theory. the atom has a positive nucleus with electrons orbiting around them like planets.
Work is considered as the Force performed on a body to move it a certain distance, that is
W = Fd
Here
W = Work
F = Force
d = Distance
In this case we have the values of work and distance, therefore clearing for the Force we would have to

Replacing,


Therefore the force that Marissa must exert on the windows shade is 0.4N
The minimum speed needed a non-propelled object to escape from the gravitational influence of a massive body, that is to achieve an infinite distance from it. I think
Mass = 1kg
Distance = 1m
Time = 1s
Force= Mass x Acceleration due to graviy
= 1 x 9.8 = 9.8
Velocity = Distance / time
= 1 / 1 =1m/s
Power = Force x velocity
= 9.8 x 1 = 9.8 W