Answer:
106.7 N
Explanation:
We can solve the problem by using the impulse theorem, which states that the product between the average force applied and the duration of the collision is equal to the change in momentum of the object:

where
F is the average force
is the duration of the collision
m is the mass of the ball
v is the final velocity
u is the initial velocity
In this problem:
m = 0.200 kg
u = 20.0 m/s
v = -12.0 m/s

Solving for F,

And since we are interested in the magnitude only,
F = 106.7 N
Answer: C Plane
Explanation: According to Newton's law, gravitational force is proportional to the product of masses and inversely proportional to the square of distance between them.
Gravitational force depends on mass. The bigger the mass, the more the magnitude of the gravitational force. Since plane is assume to have the highest mass in the options, we can therefore conclude that plane will experience the highest gravitational force.
Answer:
128.9 N
Explanation:
The force exerted on the golf ball is equal to the rate of change of momentum of the ball, so we can write:

where
F is the force
is the change in momentum
is the time interval
The change in momentum can be written as

where
m = 0.04593 kg is the mass of the ball
u = 0 is the initial velocity of the ball
is the final velocity of the ball
Substituting into the original equation, we find the force exerted on the golf ball:

Here when an object is placed on the level floor then in that case there are two forces on the object
1). Weight of object downwards (mg)
2). Normal force due to floor which will counterbalance the weight (N)
so when no force is applied on the box at that time normal force is counter balanced by weight.
Now here it is given that A person tried to lift the box upwards
So now there are two forces on the box
1). Applied force of person
2). Normal force due to ground
So now these two forces will counter balance the weight of the crate
So we can write an equation for force balance like

given that

here
m = 30 kg and
g = acceleration due to gravity = 10 m/s^2

now from above equation


So force applied by the person must be 150 N