The calculation for kinetic energy is this
KE = 1/2mv^2
KE = 1/2(50)(7^2)
KE = 1/2(49•50)
KE = 1225 kgm^2/s^2.
Or simply 1225 J.
She possess this much energy when she runs.
Answer:
1400 units of momentum.
Explanation:
Using the formula p=mv. We can get the momentum using 70*20 =1400 units of momentum
Answer:
<em>The equivalent resistance of the combination is R/100</em>
Explanation:
<u>Electric Resistance</u>
The electric resistance of a wire is directly proportional to its length. If a wire of resistance R is cut into 10 equal parts, then each part has a resistance of R/10.
Parallel connection of resistances: If R1, R2, R3,...., Rn are connected in parallel, the equivalent resistance is calculated as follows:

If we have 10 wires of resistance R/10 each and connect them in parallel, the equivalent resistance is:

This sum is repeated 10 times. Operating each term:

All the terms have the same denominator, thus:

Taking the reciprocals:

The equivalent resistance of the combination is R/100
The time after being ejected is the boulder moving at a speed 20.7 m/s upward is 2.0204 s.
<h3>What is the time after being ejected is the boulder moving at a speed 20.7 m/s upward?</h3>
The motion of the boulder is a uniformly accelerated motion, with constant acceleration
a = g = -9.8 
downward (acceleration due to gravity).
By using Suvat equation:
v = u + at
where: v is the velocity at time t
u = 40.0 m/s is the initial velocity
a = g = -9.8
is the acceleration
To find the time t at which the velocity is v = 20.7 m/s
Therefore,

The time after being ejected is the boulder moving at a speed 20.7 m/s upward is 2.0204 s.
The complete question is:
A large boulder is ejected vertically upward from a volcano with an initial speed of 40.0 m/s. Ignore air resistance. At what time after being ejected is the boulder moving at 20.7 m/s upward?
To learn more about uniformly accelerated motion refer to:
brainly.com/question/14669575
#SPJ4
Explanation:
Given that,
Weight of the engine used to lift a beam, W = 9800 N
Distance, d = 145 m
Work done by the engine to lift the beam is given by :
W = F d

Let W' is the work must be done to lift it 290 m. It is given by :

Hence, this is the required solution.