For this problem, we combine the concepts learned in physics and in calculus. The velocity, by definition, is the total distance travelled per time elapsed. It can also be expressed in Δx/Δt, This is also a definition in calculus where dx/dt is equal to velocity. Therefore, to solve the velocity, differentiate the equation in terms of t.
x = 2 cos(10t)
dx/dt = 2*(-sin(10t))*(10)
dx/dt = -20sin (10t)
We are asked to find the velocity at 0.40 seconds. Thus, we substitute t = 0.40 to the equation
dx/dt = -20sin(10*0.4)
dx/dt = v = -1.395 m/s
Therefore, the velocity at t=0.04 seconds is -1.395 m/s. The negative sign connotes that the direction of the motion is south or to the left based on the sign convention.
Answer:
Time, t = 0.104 seconds
Explanation:
Frequency of the click of the Dolphin, f = 55.3 kHz
A dolphin sends out a series of clicks that are reflected back from the bottom of the ocean 80 m below, d = 80 m
The speed of sound in seawater is, v = 1530 m/s
Once the sound is send and reflects, the total distance covered by it is 2d such that,
So, the time elapses before the dolphin hears the echoes of the clicks is 0.104 seconds.
Answer:
The initial energy emission occurs by 80% or more in the form of gamma rays but these are quickly absorbed and dispersed mostly by air in little more than a microsecond, converting gamma radiation into thermal radiation (thermal pulse ) and kinetic energy (shock wave) which are actually the two dominant effects in the initial moments of the explosion. The rest of the energy is released in the form of delayed radiation (fallout or fallout) and is not always counted when measuring the performance of the explosion.
Explanation:
High altitude explosions produce greater damage and extreme radiation flux due to lower air density (photons encounter less opposition) and consequently a higher blast wave is generated.
A billiard ball moves with 3 kg⋅m/s of momentum and strikes three other billiard balls that have been just sitting there at rest and not moving.
The total momentum of all four balls after the collision is <em>3 kg⋅m/s</em>, because momentum is not created or destroyed. The total amount of it after an event is the same as the total amount of it before the event.
Answer:
Option C. 16.6 m/s
Explanation:
To round this 16.558 m/s to 3sf, we need to count the number beginning from 1. When we get to the 3rd number( ie 5), we'll examine the fourth number(i.e 5)to see if it less than five or greater. If it less than five, then we'll discard it. But if it five or greater, we'll approximate it and add it to the 3rd number.
So.
16.558 m/s = 16.6m/s to 3sf
