All categories

3 years ago

When jumping, a flea accelerates at an astounding 1500 m/s2 , but over only the very short distance of 0.41 mm ?

1 answer:

4 0

<span>V² = 2*a*y = 1.17 m²/s² at 0.45 mm height

H = V²/(2g) + 0.00045 = 0.0597 + 0.00045 = 0.06014 m = 6.014 cm </span>

You might be interested in

Which of the following occurs on March 21?

iren [92.7K]

Vernal equinox, for spring.

6 0

3 years ago

What happens to the particles in a medium when waves propagate through the medium

jeka94

Answer:

they move in the direction of propagation/the angle of propagation

Explanation:

7 0

3 years ago

A car goes from 80 kn/h to 20 km/h in 0.5 h. What is the acceleration in km/h^2? *

jekas [21]

Answer:

<h2>In physics, acceleration is defined as the rate of change of the velocity of an object with respect to time. That is A = VF - VI /T; </h2><h2></h2><h2>Where A = Acceleration </h2><h2>VF = Final velocity = 20 km </h2><h2>VI = Initial velocity = 80 km </h2><h2>T= Time = 0.5 hr </h2><h2>A = (20 - 80)/ 0.5 = - 60/.5 </h2><h2>A = - 120 Km/ hr^2 </h2><h2></h2><h2>Therefore, the acceleration of the car is -120 km/hr^2. </h2><h2> Because the value is negative, the appropriate name that describe it is deceleration.</h2><h2>I Hope this helps</h2>

3 0

3 years ago

A ball is thrown vertically downward from the top of a 37.4-m-tall building. The ball passes the top of a window that is 15.4 m

Effectus [21]

Answer:

v= 20.8 m/s

Explanation:

Assuming no other forces acting on the ball, from the instant that is thrown vertically downward, it's only accelerated by gravity, in this same direction, with a constant value of -9.8 m/s2 (assuming the ground level as the zero reference level and the upward direction as positive).
In order to find the final speed 2.00 s after being thrown, we can apply the definition of acceleration, rearranging terms, as follows:

$v_{f} = v_{o} + a*t = v_{o} + g*t (1)$

We have the value of t, but since the ball was thrown, this means that it had an initial non-zero velocity v₀.
Due to we know the value of the vertical displacement also, we can use the following kinematic equation in order to find the initial velocity v₀:

$\Delta y = v_{o} *t + \frac{1}{2} * a* t^{2} (2)$

where Δy = yf - y₀ = 15.4 m - 37.4 m = -22 m (3)

Replacing by the values of Δy, a and t, we can solve for v₀ as follows:

$v_{o} = \frac{(\Delta y- \frac{1}{2} *a*t^{2})}{t} = \frac{-22m+19.6m}{2.00s} = -1.2 m/s (4)$

Replacing (4) , and the values of g and t in (1) we can find the value that we are looking for, vf:

$v_{f} = v_{o} + g*t = -1.2 m/s - (9.8m/s2*2.00s) = -20.8 m/s (5)$

Therefore, the speed of the ball (the magnitude of the velocity) as it passes the top of the window is 20.8 m/s.

4 0

3 years ago

An astronaut floating at rest in space throws a wrench in one direction and subsequently recoils back with a velocity in the opp

Jobisdone [24]

Answer:

a) ll and Ill only

Explanation:

Let the mass of the wrench = m

and the mass of the astronaut = M

Initially, the velocity of the astronaut and wrench are zero.

The astronaut throws the wrench in one direction and subsequently recoils back with a velocity in the opposite direction.

Let v and V be the velocity of the wrench and the velocity of the astronaut respectively.

In space, there is no external force acting, the momentum must be conserved.

So, m(0)+M(0)=m(v)+M(V)

So, 0=mv+MV

$\Rightarrow mv=-MV$ ...(i)

Here, the momentum of the wrench = mv, and the momentum of the astronaut= MV. The negative sign showing that both the momentum are in opposite direction.

Therefore, the momentum of the wrench is equal and opposite to the momentum of the astronaut.

According to Newton's second law, the rate of change of momentum = applied force.

Let it take $\Delta t$ seconds to change the momentum.