Answer:
we learned that an object that is vibrating is acted upon by a restoring force. The restoring force causes the vibrating object to slow down as it moves away from the equilibrium position and to speed up as it approaches the equilibrium position. It is this restoring force that is responsible for the vibration. So what forces act upon a pendulum bob? And what is the restoring force for a pendulum? There are two dominant forces acting upon a pendulum bob at all times during the course of its motion. There is the force of gravity that acts downward upon the bob. It results from the Earth's mass attracting the mass of the bob. And there is a tension force acting upward and towards the pivot point of the pendulum. The tension force results from the string pulling upon the bob of the pendulum. In our discussion, we will ignore the influence of air resistance - a third force that always opposes the motion of the bob as it swings to and fro. The air resistance force is relatively weak compared to the two dominant forces.
The gravity force is highly predictable; it is always in the same direction (down) and always of the same magnitude - mass*9.8 N/kg. The tension force is considerably less predictable. Both its direction and its magnitude change as the bob swings to and fro. The direction of the tension force is always towards the pivot point. So as the bob swings to the left of its equilibrium position, the tension force is at an angle - directed upwards and to the right. And as the bob swings to the right of its equilibrium position, the tension is directed upwards and to the left. The diagram below depicts the direction of these two forces at five different positions over the course of the pendulum's path.
that's what I know so far
Average Velocity = Total Displacement / Total time
1st part of journey, 350 km at velocity 125 km/h
Time = 350 / 125 = 2.8 hours.
2nd part of journey, 220 km at velocity 115 km/h
Time = 220 / 115 = 1.9 hours
Average Velocity = Total Displacement / Total time
= (350 + 220) / (2.8 + 1.9)
= 570 / 4.7 ≈ 121.3 km/hr
Average Velocity ≈ 121 km/hr due south.
Option C.
Answer:
6.0 m/s
Explanation:
According to the law of conservation of energy, the total mechanical energy (potential, PE, + kinetic, KE) of the athlete must be conserved.
Therefore, we can write:
or
where:
m is the mass of the athlete
u is the initial speed of the athlete (at the bottom)
0 is the initial potential energy of the athlete (at the bottom)
v = 0.80 m/s is the final speed of the athlete (at the top)
is the acceleration due to gravity
h = 1.80 m is the final height of the athlete (at the top)
Solving the equation for u, we find the initial speed at which the athlete must jump:
Answer:
hmm if it were up to me i would say gravity potential energy and sorry I don't really have a third one hope this helps though.
Answer:
original mass of the block of ice is 38.34 gram
Explanation:
Given data
cup mass = 150 g
ice temperature = 0°C
water mass = 210 g
water temperature = 12°C
ice melt = 2 gram
to find out
solution
we know here
specific heat of aluminum is c = 0.900 joule/gram °C
Specific heat of water C = 4.186 joule/gram °C
so here temperature difference is dt = 12- 0 = 12°C
so here heat lost by water and cup are given by
heat lost = cup mass × c × dt + water mass × C × dt
heat lost = 150 × 0.900 × 12 + 210 × 4.186 × 12
heat lost = 12168.72 J
so
mass of ice melt here = heat lost / latent heat of fusion
here we know latent heat of fusion = 334.88 joule/gram
so
mass of ice melt = 12168.72 / 334.88
mass of ice melt is 36.337554 gram
so mass of ice is here = mass of ice melt + ice melt
mass of ice = 36.337554 + 2
mass of ice = 38.337554 gram
so original mass of the block of ice is 38.34 gram
