Answer:
4.5kgm/s
Explanation:
Change in momentum is expressed as
Change in momentum = m(v-u)
M is the mass
V is the final velocity
u is the initial velocity
Given
m=0.45kg
v = 30m/s
u = 20m/s
Substitute
Change in momentum = 0.45(30-20)
Change in momentum = 0.45×10
Change in momentum = 4.5kgm/s
Answer:
the kinetic energy lost due to friction is 22.5 J
Explanation:
Given;
mass of the block, m = 0.2 kg
initial velocity of the block, u = 25 m/s
final velocity of the block, v = 20 m/s
The kinetic energy lost due to friction is calculated as;

Therefore, the kinetic energy lost due to friction is 22.5 J
The just-world phenomenon is the belief that everything that happens to an individual is due to the individual's actions; in other words, all good and all bad that an individual encounters in the world is deserved by that person. This leads to a victim being blamed with the logic that "they had it coming" and someone who encounters good fortune being praised with "they earned it". Therefore, in this scenario, people will assume that Rose's inheritance is well deserved.<span />
There are missing data in the text of the problem (found them on internet):
- speed of the car at the top of the hill:

- radius of the hill:

Solution:
(a) The car is moving by circular motion. There are two forces acting on the car: the weight of the car

(downwards) and the normal force N exerted by the road (upwards). The resultant of these two forces is equal to the centripetal force,

, so we can write:

(1)
By rearranging the equation and substituting the numbers, we find N:

(b) The problem is exactly identical to step (a), but this time we have to use the mass of the driver instead of the mass of the car. Therefore, we find:

(c) To find the car speed at which the normal force is zero, we can just require N=0 in eq.(1). and the equation becomes:

from which we find
The answer would be C. It will decrease with descent. Hope this helps!