Answer:
averaage speed is v = 13 feet / s
Explanation:
The average speed is the ratio of the distance traveled in a given time interval, let's calculate the distance that the body travels in the two instants of time that give us
t = 1 s
d (1) = 2.6667 1²
d (1) = 2.6667 feet
t = 4 s
d (4) = 2.6667 4²
d (4) = 42.6672 feet
Let's calculate the speed
v = Δx / Δt
v = (42.6672 -2.6667) / (4-1)
v = 40/3
v = 13.33335 feet / s
v = 13 feet / s
<span>14 m/s
Assuming that all of the energy stored in the spring is transferred to dart, we have 2 equations to take into consideration.
1. How much energy is stored in the spring?
2. How fast will the dart travel with that amount of energy.
As for the energy stored, that's a simple matter of multiplication. So:
20 N * 0.05 m = 1 Nm = 1 J
For the second part, the energy of a moving object is expressed as
KE = 0.5 mv^2
where
KE = Kinetic energy
m = mass
v = velocity
Since we now know the energy (in Joules) and mass of the dart, we can substitute the known values and solve for v. So
KE = 0.5 mv^2
1 J = 0.5 0.010 kg * v^2
1 kg*m^2/s^2 = 0.005 kg * v^2
200 m^2/s^2 = v^2
14.14213562 m/s = v
So the dart will have a velocity of 14 m/s after rounding to 2 significant figures.</span>
Answer:
the value of vA that will allow the car to coast in neutral so as to just reach the top of the 150 m high hill at B with vB = 0 is 31.3 m/s
Explanation:
given information
car's mass, m = 1200 kg
= 100 m
=
= 150 m
= 0
according to conservative energy
the distance from point A to B, h = 150 m - 100 m = 50 m
the initial speed
final speed = 0
thus,
² = ² - 2 g h
0 = ² - 2 g h
² = 2 g h
= √2 g h
= √2 (9.8) (50)
= 31.3 m/s
Two methods of transfer of heat are involved in this process: conduction and convection.
In fact, the metal spoon is heated by conduction because the molecules of the boiling water collide with the molecules of the spoon, releasing heat to it; and also by convection, because in the pot of boiling water masses of hot water goes upward and they give their heat to the spoon, then these masses become cooler and they go down, replaced by other masses of hot water.
<span>The skier will transform their gravitational energy into mostly kinetic energy (with a minor amount transformed into heat from the friction of the skis across the snow and air friction). Once the skier hits the snowdrift, their kinetic energy is transferred into the snow which moves when they strike it due to the kinetic energy that is now in the snow. Along with again a minor amount of heat energy transferred as they move through the snowdrift.</span>
