Answer:
Explanation:
The gravitational force acting on the ball, F = 10 N (down) The air resistance acting on the ball, f = 1 N (up) We need to find the magnitude of net force acting on the ball. The net force is given by : F' = 9 N. So, the net force acting on the ball is 9 N in downward direction. Hence, this is the required solution
Answer:
The statement that refers to convection is Warm air rises and takes heat with it; eventually it cools and sinks
Explanation:
There are in general three modes of heat transfer: conduction, convection and radiation.
- In conduction, the heat transfers through contact
- In convection, the heat transfers through density difference
- In radiation, the heat transfers through wave motion
Consider first statement, 'Land and ocean absorb and re-emit heat from the sun'. Radiation is the only mode of heat transfer where there is no requirement for medium. The heat from sun to land and ocean has traveled by radiation. The process of re-emission also occurs in the same way.
Similarly in second statement the energy reflected of earth's atmosphere traveled by radiation and the last statement where sunlight travels through space without aid of fluids or solids refers to the process of radiation.
In third statement the warm air being less dense rises and takes heat with it; eventually it cools and thereby density increases which causes to sink. Here the movement of air is due to density difference, which concludes that this statement refers to convection
Answer:
288 Joules
Explanation:
Work= delta kinetic energy. To find the work required to stop the kitten, you have to find the delta kinetic energy between when the kitten is moving and when it is stopped. Since it is not moving when it's stopped, it has no kinetic energy. So to find the work, just find the kinetic energy of the kitten moving at 12m/s.
KE=1/2((m)(v^2)), therefore
delta KE=(1/2)*((4kg)*((12m/s)^2))-0
Answer:
2.286 km/s²
Explanation:
Since acceleration a = (v - u)/t where u = initial horizontal velocity of ball = 0 m/s (since it starts from rest), v = final horizontal velocity of ball at serve = 73.14 m/s and t = time taken for serve = 32.0 ms = 0.032 s
Substituting the values of the variables into the equation, we have
a = (v - u)/t
a = (73.14 m/s - 0 m/s)/0.032 s
a = 73.14 m/s/0.032 s
a = 2285.625 m/s²
a = 2.285625 km/s²
a ≅ 2.286 km/s²
So, the x - component of the ball's acceleration during the serve is 2.286 km/s²
Answer:
Explanation:
According to Coulomb's law, the magnitude of the force (F) between two objects with the same charge(+Q), separated a distance (d) apart, is defined as:
Here k is the Coulomb constant. The charge on each object is doubled, that is :