Answer: a) 7.1 * 10^3 N; b) -880 N directed out of the curve.
Explanation: In order to solve this problem we have to use the Newton laws, then we have the following:
Pcos 15°-N=0
Psin15°-f= m*ac
from the first we obtain N, the normal force
N=750Kg*9.8* cos (15°)= 7.1 *10^3 N
Then to calculate the frictional force (f) we can use the second equation
f=P sin (15°) -m*ac where ac is the centripetal acceletarion which is equal to v^2/r
f= 750 *9.8 sin(15°)-750*(85*1000/3600)^2/150= -880 N
A displacement is a vector quantity that takes into account the shortest distance from the starting point to the endpoint.
The given above gave a time interval in minutes which needs to be converted to seconds. Given that each minute is 60 seconds, 5 minutes equal 300 seconds. To determine the distance, multiply time with speed. The product is 225 m.
Thus, the displacement is 225 m.
If you saturated the solid it will turn into liquid and soon become an air
Answer:
4.6 
Explanation:
Since the table is frictionless, there is no force of dynamic friction between table an block when the horizontal force is applied to it on Earth. Exactly the same is true when the table is taken to the Moon. Therefore, the Net Force acting on the object in both cases when the object accelerates, is the external horizontal force.
Notice that on Earth and on the Moon, the weight of the object (vertical and pointing up) is compensated by the normal force of the table on the object (pointing up and of the same magnitude as the weight) that precludes movement in the vertical direction. So in both cases, its acceleration will only be due to the horizontal force.
We use the equation for Net Force to find the mass of the object:

We use this mass (since the mass of the object is a constant independent of where the object is) to find the acceleration the object will experience when the 20 N horizontal force is applied on it on the Moon:

We can solve the problem by using conservation of momentum.
The player + ball system is an isolated system (there is no net force on it), therefore the total momentum must be conserved. Assuming the player is initially at rest with the ball, the total initial momentum is zero:

The total final momentum is:

where
is the momentum of the player and
is the momentum of the ball.
The momentum of the ball is: 
While the momentum of the player is:
, where M=59 kg is the player's mass and vp is his velocity. Since momentum must be conserved,

so we can write

and we find

and the negative sign means that it is in the opposite direction of the ball.