Answer:
Explanation:
deceleration a
v² = u² - 2as
0 = 7.5² - 2 a x .15
a = 187.5 m / s²
If R be the force exerted by hand
R- mg = ma
R = mg + ma
= .27 ( 9.8 + 187.5 )
= 53.27 N
Work done by hand
= force x displacement
= 53.27 x - .15
= - 8 J
Answer:
Explanation:
m = Mass of water = 2 kg
c = Specific heat of water =
= Change in temperature =
Change in thermal energy is given by
Cale's change in thermal energy was .
Answer:
a) the distance the ball moves up the ramp is approximately 9.35 meters
b) the tme required for the ball to return to the girls' hands is 6.34 seconds
Explanation:
The movement of the ball can be describe by a rectilinear movement with constant (negative) acceleration of 0.19 g = 1.862 m/s^2
Therefore the kinematic equations for the case the girl launches the ball at 5.9 m/s, we can write:
We use the second equation above to find the time it takes for the velocity to reduce to zero (and start the movement back down the ramp), and then use the time found to calculate the distance;
We use this time to find the distance the ball moves up the ramp:
so the distance the ball moves up the ramp is approximately 9.35 meters
The ball will return to the hands of the girl in the double of the time it took to reach the max distance, that is 2 times 3.17 sec = 6.34 sec
Non metals tend to have higher ionization energies
m = mass of the person = 82 kg
g = acceleration due to gravity acting on the person = 9.8 m/s²
F = normal force by the surface on the person
f = kinetic frictional force acting on the person by the surface
μ = Coefficient of kinetic friction = 0.45
The normal force by the surface in upward direction balances the weight of the person in down direction , hence
F = mg eq-1
kinetic frictional force on the person acting is given as
f = μ F
using eq-1
f = μ mg
inserting the values
f = (0.45) (82) (9.8)
f = 361.6 N