The cart experiences a frictional force which is directly proportional to its weight. This means that there must be a force applied on the car to balance the forces on the car to produce a net force of 0.
This is in accordance to Newton's first law which states that an object at rest will remain at rest and an object in motion will remain in motion unless an external force acts on it. The force must be a resultant force.
Therefore, the force needed increases with the total weight of the cart as well as with the added mass in a linear manner.
Answer:
K = 0.076 J
Explanation:
The height of the target, h = 0.860 m
The mass of the steel ball, m = 0.0120 kg
Distance moved, d = 1.50 m
We need to find the kinetic energy (in joules) of the target ball just after it is struck. Let t is the time taken by the ball to reach the ground.

Put all the values,

The velocity of the ball is :

The kinetic energy of the ball is :

So, the required kinetic energy is 0.076 J.
Answer:
3.2N
Explanation:
Given parameters:
Mass of block = 1.5kg
Coefficient of kinetic friction = 0.6
Force of pull on block = 12N
Unknown:
Net force on the block = ?
Solution:
Frictional force is a force that opposes motion:
Net force = Force of pull - Frictional force
Frictional force = umg
u is coefficient of kinetic friction
m is the mass
g is the acceleration due to gravity
Frictional force = 0.6 x 1.5 x 9.8 = 8.8N
Net force = 12N - 8.8N = 3.2N
The frequency doesn't change as the wave crosses
the boundary between one medium and another.