Answer:
step bro was stuck on the elevator
Explanation:
Answer:
v2 = 27.3m/s
Explanation:
Assuming forward as positive.
Mass = m1 = 64kg
Let v be the common velocity of the student and the skateboard.
mass of skateboard = m2 = 5.94kg
v = 1.4m/s
Since the skateboard and the student are initially moving together at the same velocity their momentum together is
(m1 + m2)v
Let the final velocity of the student be v1 and the final velocity of the skateboard be v2
v1 = – 1.0m/s (falls backwards that's why the velocity is negative since we are assuming forward as positive)
Then from conservation of momentum, momentum before is equal to momentum after.
(m1 + m2)v = m1v1 + m2v2
m2v2= (m1 + m2)v – m1v1
v2 = ( (m1 + m2)v – m1v1)/m2
v2 = ( (64 + 5.94)×1.4 – 64×(-1.0))/5.94
v2 = ( (64 + 5.94)×1.4 + 64×1.0)/5.94
v2 = 27.3m/s
<span>A motor produces less mechanical energy than the energy it uses because the motor looses some energy to heat.</span>
Answer:
1) D, 2) D, 3) B, 4) B, 5) C
Explanation:
You are asked to select the correct answer
1) The conservation of energy is one of the most important principles of physics that allows solving countless problems in life.
the correct answer is D
2) when a body falls, the gravitational potential energy is transformed into kinetic energy and both are transformed into thermal energy
the correct answer is D
3) When the gravitational potential energy is maximum, the kinetic energy is minimum and when the kinetic energy is maximum, the gravitational energy is minimum.
Correct answer B
4) speed is defined by
v = x / t
so the correct answer is B in the SI system
5) when we repeat a measurement several times, the random or statistical errors decrease, therefore the confidence of the measurement increases.
The correct answer is C
